Mexican Chicken Fajita Casserole

by Shelley · May contain affiliate links

Published

~ This family-favorite Mexican Chicken Fajita Casserole has all the flavors of restaurant-style chicken fajitas, in a super-simple baked dinner! Bonus: the base features protein-packed Mexican black beans and quinoa … with no pre-cooking needed (and you mix it up right in the baking dish). Seriously delicious, and soooooo easy! ~

(Originally published as Chicken Fajita Quinoa Bake {No Pre-Cooking!} on March 6, 2014. Updated photos, text and tips.)

This Recipe Is:     Make Ahead    Gluten Free  

Flatlay of finished casserole with serving spoon tucked in on wooden board; Mexican toppings waiting alongside.

This is how a family-favorite, restaurant-quality fajita dinner can actually happen, on even the busiest of nights.

And you’re the hero who delivers piping-hot chicken fajitas to the table, deliciously nestled in a cozy casserole dish. (No tortillas or messy jamming-the-fillings-into-a-wrap needed.)

And yep … you make it look easy! Because it IS!

I’m not exaggerating when I tell you this casserole is 100% THAT terrific. I’ve been making it for 10 years now (and first shared it here on my website back in 2014). Yet my family falls in love all over again, every single time they see it heading to the table.

#truth

The 3 Reasons You’ll LOVE This Chicken Fajita Casserole Recipe!

✔ Reason 1: It’s Crazy-Delicious!

I mean … chicken fajitas. Yum. Of course, that involves:

  • succulent, juicy chicken strips
  • crisp-tender onions and bell peppers
  • … all tossed in a super-simple but super-yummy blend of Mexican fajita spices

But then it gets even better. All that fajita-y goodness is perched on top of a glorious layer of:

  • salsa-flavored black beans and whole grains (Surprise – we’re substituting quinoa for boring ol’ rice – and you’ll be so glad we did!)
Closeup of upper right corner of casserole dish so you can see the melty cheese over the fajita veggies and chicken.

It’s fabulous straight outta the pan, or you can melt cheese on top, or you can toss on some traditional fajita toppings … whatever you feel like.

Yum yum and YUM!

✔ Reason 2: It’s So Darn EASY (Cheater Alert!)

Like I mentioned before, this meal can happen on even busy, busy weeknights. And you won’t even break a sweat as you flex your dinner-hero muscles and whip this up in a twinkling.

It calls on a couple of my favorite, speedy cheats: mix stuff up right in the pan, and don’t pre-cook anything you don’t have to.

That’s right. You don’t even have to pre-cook the quinoa, because it cooks merrily along with the rest of the casserole in the oven.

And you mix your casserole’s base layer right in your baking dish, instead of dirtying an additional bowl.

Oh! And you can either (1) prep it partially ahead or even (2) {woot woot!!} make it entirely ahead of time and quickly re-warm it whenever dinnertime happens to actually happen.

✔ Reason 3: It’s So Nutritious, Too!

Yep. As if you weren’t feeling fantastic enough already, serving up fajitas everybody loves, in the blink of an easy-peasy eye!

Well, you’re gonna feel even better because all that deliciousness your entire family is raving about (and stuffing in their mouths) is actually GOOD for them, too!

Overhead of lower corner of casserole dish with fajita toppings like shred cheese, avocado and cilantro at right.

Lean chicken, loads of fajita veggies, black beans, PLUS protein- and fiber-packed quinoa!

With all of its nutritious upgrades, quinoa is a great choice to replace the rice you often find in typical, old-school Mexican chicken casseroles. (We use it as a starting base in other casseroles, too – like our Comforting Stuffed Pepper Casserole and our Italian Stuffed Zucchini Boats Casserole.) It works beautifully and adds such a wonderful nutrition boost!

You might also notice that some of the other Mexican chicken bake recipes out there involve calorie-laden ingredients like cream cheese, cream of chicken soup, or layers of tortilla chips. But that’s certainly not a healthy way to go, and mostly doesn’t fit with the fajita concept here, anyway. Simple ingredients are all you need in this family favorite, trust me!

So, yeah. You’re gonna feel great about this for ALLLLLL the reasons.

Ya ready??? Ok then! Let’s tackle this incredible fajita casserole recipe …

How to Make Your Easy Mexican Chicken Casserole

Another great thing about this recipe (as if it wasn’t great enough already) is that many of the ingredients you need are shelf-stable.

Flatlay of ingredients on cutting board including raw chicken breasts, whole vegetables, uncooked quinoa and dish of spices.

So you can keep most of it on hand, ready to toss together a cozy, comforting dinner with just a quick trip to grab some chicken and fresh produce. (Making it even easier to be a family Dinner Hero, with only the tiniest smidge of effort!)

Choosing Peppers and Onions

I prefer to make this recipe with a mellow, sweet onion and a colorful mix of red and green bell pepper.

But, if you prefer, you could go with (slightly “spicier”) yellow onion or even red onion (like we do with our Baked Shrimp Fajitas). And, you can mix up the pepper colors however you please. I will say, though, that I do like that red bell peppers are less bitter-tangy than using only green peppers alone. Orange or yellow bell peppers would offer a sweeter flavor, similar to a red pepper. See what looks good at your grocery store – the choice is really yours!

Ingredient Prep

Start by slicing your peppers and onion into fajita-sized strips.

You should end up with about 1½ cups of each pepper (3 cups of peppers total), and 1¾ – 2 cups of onion strips. But it’s pretty hard to shove veggie strips into a 1-cup measure, and you truly don’t have to be THAT precise. As long as you’re more or less in the ballpark, the amount should be just fine.

Flatlay of chicken, onion and peppers, all sliced into fajita strips on cutting board.

Similarly, slice your chicken breasts (or tenders) into fajita-sized, thin strips.

If you’re using tenders, it’s not strictly necessary to cut them down thinner, if you’re in a hurry. But if you have the time, I recommend cutting tenders (especially the larger ones) in half lengthwise. That creates thinner strips, with more surface area to be coated in the delicious fajita spices.

Prep Ahead!

You can slice up your veggies and chicken earlier in the day, or the day before you’re actually planning to serve your Mexican Chicken Casserole. Pop each ingredient into a separate, airtight container or baggie in the fridge … so tossing this recipe together at the last minute becomes even faster and EASIER than it already is!

When you’re ready to cook, here’s all you do …

Step #1

Preheat your oven to 400°F.

This hardly even counts as a step! Easy so far, right?!?

Step #2

Now here’s where the big cheater moves come in. Remember I told you about these?

You get to skip an ENTIRE cooking step! I know, right!?!? How cool is that!?!

You don’t have to pre-cook the quinoa!

And you don’t need an extra bowl here, either. Simply mix up your salsa, black beans, chicken broth, and quinoa right in a 9×13 baking dish. (I like to coat it with cooking spray first.)

The Magic of NOT Pre-Cooking Your Quinoa

When it first occurred to me to try cooking quinoa this way (back 10 or 11 years ago), I wondered if it would actually work. And why (if it did work) I hadn’t come across more recipes that used this {magical} method.

It seems so logical, right? If you can bake pasta without pre-cooking it (hint hint … try our 5-Ingredient Pizza Pasta Bake!) well, then why couldn’t quinoa work the same way? (These are the kinds of questions that keep food bloggers awake at night.)

If you follow THK, you know we did a big ol’ post about all the ins and outs of cooking quinoa. So, I’ve done a fair amount of research and testing when it comes to my pal, quinoa.

Still, I was so excited about the no-pre-cooking idea. Why hadn’t I seen this before? (Why, oh why, hadn’t I tried it before???) After all – you, my THK friends, know that I loooooove to skip steps if it gets a delicious dinner on the table even faster!

So I gave it a try. (I mean … what better way to see what would happen?)

I was actually shocked (and ridiculously excited) to find that … IT WORKED! Like a charm, actually! Truly like MAGIC!

Step #3

Ok, so once you’re done being crazy-excited about how easy the base layer is … it’s on to the also-easy step of adding BIG fajita flavor to your chicken and vegetables.

All you have to do here is toss your strips of peppers, onion and chicken with a bit of oil, and a super-simple seasoning combo of chili powder, cumin, garlic powder and salt.

Nothing fancy, but I promise it is so flavorful and soooooo good!

Then, you just spoon that fajita-seasoned chicken mixture over the quinoa mixture that’s waiting in your baking dish.

And it’s ready to pop in the oven!

Overhead of seasoned chicken and vegetables spread atop Mexican quinoa and black bean layer, ready to bake.

Step #4

Bake your Fajita Chicken Casserole (covered with foil) for about 40-50 minutes.

The exact cooking time will depend on the thickness of your chicken and peppers, and on your brand of quinoa.

Basically, you’re looking for your chicken to be cooked through, for your veggies to be crisp-tender, for the liquid to be mostly absorbed, and for your quinoa to be done.

Checking Your Quinoa for Doneness

Quinoa’s perfectly cooked when most of it no longer looks like tightly closed white dots, but instead is tender with lots of visible quinoa “tails.”

In addition, although the base layer of your casserole may still be a little loose (it thickens some upon standing), you don’t want it to be really wet.

Overhead of partially baked casserole on cutting board so you can see the broth and not-quite-cooked quinoa.

If you look closely at the picture above, you’ll see that only a few quinoa tails have appeared, and it’s still pretty brothy.

It’ll be ok at this stage, but I’d really recommend giving it a few more minutes in the oven for total “Casserole PERFECTION”!

Then, all that’s left to do is carry it to the table!

And looky there … see all those eager, smiling faces, as your family cheers and happily grabs their forks? Uh-huh. You did that. You made this dinner moment happen!

(And you don’t have to admit how easy it actually was. Bask in the praise, my friend. The glory is yours!)

How to Serve This Mexican Casserole Recipe

This recipe is, at its core, basically just chicken fajitas, reinvented in casserole form.

So, it makes sense to serve it up with your family’s favorite fajita toppings.

The usual suspects are shredded lettuce, chopped fresh cilantro, maybe even some chopped tomatoes or a squeeze of lime juice. Black olives, sliced green onions and canned green chiles could work, too. And I’d definitely vote for guacamole or chopped avocados. Salsa or hot sauce, if you’d like. Oooooh … how about some sour cream and cheddar cheese? (YES!)

Cheesy Options

You can certainly opt to simply offer shredded cheese at the table, and everyone can sprinkle on their own.

But for maximum, ooey-gooey-cheesy WOW factor, I like to sprinkle a little cheese on top of the finished casserole as it comes out of the oven, and then pop the baking dish back in, just long enough for the cheese to get melty.

Two hands holding up finished casserole in white baking dish with Mexican toppings nearby.

You can run it under the broiler, too, if you want that browned-and-bubbled vibe. Mmmmmm … gooey cheese!

And what about side dishes?

Well, honestly, this Mexican Chicken Fajita Casserole is truly a complete meal-in-one.

At Mexican restaurants, classic fajitas are normally served with a side of refried beans and Mexican rice. But we’ve already worked black beans into the casserole, and we’ve got quinoa standing in for the rice … so there’s honestly no need to fuss with side dishes. And you can totally skip the flour tortillas, of course. Simple, simple!

But if you’d like to create an all-out Mexican fiesta (hey hey … like for a Cinco de Mayo feast!), I absolutely recommend this Mexican Street Corn Salad or this Corn Salsa (which doubles as a side salad).

You can be an absolute Dinner Hero, without even making a side dish, though. Really!

FAQs At-a-Glance

Can You Make This Mexican Casserole Ahead of Time?

You sure can! As mentioned above, you can prep and slice ingredients ahead of time. But you can also completely finish the recipe and bake the casserole ahead of time, cool it down and refrigerate it (as directed in the Notes section of the recipe card below). It’s great for meal prep, since you can reheat individual portions as needed. Just be sure to reheat it gently, so you don’t overcook the chicken.

How Healthy Is Fajita Chicken?

Well, that depends on factors like how much oil (with its added fat and calories) is used to sizzle up the chicken strips, and how much white rice or how many white-carb tortillas are along for the ride. In this fajita-style Mexican Chicken Casserole, we address the dilemma on multiple fronts, by limiting the calorie-filled oil, by working in lots of veggies, and by pumping up the fiber and protein with black beans and quinoa (instead of white rice).

What Spices and Seasonings Are Common in Fajitas?

The precise spice combination varies. It’s somewhat similar to taco seasoning, but fajita blends usually have a few extra spices and generally don’t include the cornstarch that’s often used as a thickener in taco blends. As an example, our basic, “classic” Homemade Fajita Seasoning includes 8 ingredients (garlic powder, chili powder, cumin, onion powder, salt, paprika, black pepper, and oregano), which is perfect for our Shrimp Fajitas. Not all of those spices are needed, though, in the simplified spice mixture we use in this casserole recipe (since we’re already packing in Mexican flavor from the jar of salsa).

Is Quinoa a Gluten-Free Grain?

Yep … quinoa is gluten-free. But, as we discuss in our article “How to Cook Quinoa (and Why You Should!)” it’s not technically a grain, even though it’s often lumped into discussions about whole grains. Fun fact alert: according to the Whole Grains Council, quinoa is actually botanically related to beets, chard and spinach.

Why Does Quinoa Have to Be Rinsed?

Quinoa has a bitter coating (called saponin) that naturally protects the crop against pests. That’s why it’s so easy to grow quinoa without pesticides and why quinoa is often able to be sold as organic – bonus! But, you want that bitter saponin layer to be rinsed away so it’s delicious to eat. Some brands are labeled as pre-rinsed, but all you need to do to rinse it at home is swish the quinoa in a sieve under running water until the water runs clear.

Bottom line: this fajita bake is always such an easy dinner and always, always so crazy-good!

Like I said, this recipe has been a fan favorite at my house for nearly a decade. (And always a great option on a busy weeknight!)

It’s the kind of meal where you keep scooping a tiny bit more onto your plate … and then just a tiny smidgen more … and then maybe just a little …

Because it’s too good to stop eating.

And I always feel fantastic knowing that I made a dinner my family enjoys this much, without fussing or stressing at all. Knowing that they truly love it … and that it’s also extra nutritious and good for them, too.

Left corner of baking dish with finished casserole, melted cheese, scallions and cilantro atop vegetables and chicken.

Whenever I make it, I feel like I’m winning on all fronts.

As dinner recipes go, this one’s a serious hero-maker. For oh-so-many reasons.

I hope you’re a Dinner Hero tonight, too, my friend! Enjoy!

~ by Shelley

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Please leave a star-rating in the recipe card below – I truly appreciate all your wonderful feedback!

Closeup overhead of one corner of casserole dish with spoon dipped into finished recipe, cheese, avocado and cilantro alongside.

Mexican Chicken Fajita Casserole

The family-pleasing flavors of chicken fajitas, in a simple baked casserole! So easy, so delicious … a favorite for nearly a decade!
• Make Ahead • Gluten Free •
4.91 from 10 votes
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Prep Time: 15 minutes
Cook Time: 40 minutes
Total Time: 55 minutes
Yield: 13 cups (8 servings)

Ingredients
 

  • 1 (16-ounce) jar of your favorite thick and chunky salsa (see note)
  • 1 (15-ounce) can black beans, rinsed and drained
  • 1 (14.5-ounce) can fat-free, reduced-sodium chicken broth
  • 1 cup uncooked quinoa (rinsed if needed – see note)
  • 1 red pepper, cut into strips (to equal about 1½ cups)
  • 1 green pepper, cut into strips (to equal about 1½ cups)
  • ½ of a large sweet onion, cut into strips (to equal about 1¾ – 2 cups)
  • 1 pound chicken breasts, cut into strips, or 1 pound chicken tenders (see note)
  • 1 tablespoon olive oil
  • 3 teaspoons chili powder
  • teaspoons ground cumin
  • 2 teaspoons garlic powder
  • teaspoons kosher salt
  • optional toppings for serving: shredded reduced-fat cheese, shredded lettuce, reduced-fat sour cream, avocados or guacamole, chopped cilantro or green onions, hot sauce such as Tapatío

Instructions
 

  • Preheat oven to 400 °F.
    Flatlay of ingredients on cutting board including raw chicken breasts, whole vegetables, uncooked quinoa and dish of spices.
  • Mix salsa, black beans, chicken broth, and quinoa in a 9×13 baking dish coated with cooking spray.
    Hands holding casserole dish and wooden spoon, mixing Mexican black beans, salsa and quinoa base.
  • In a large bowl, combine peppers, onion, chicken, oil, and seasonings until thoroughly combined. Spoon pepper mixture over quinoa mixture in baking dish.
    Flatlay of chicken and vegetables in bowl, mixed with Mexican spices; empty salsa bowl and waiting casserole dish nearby.
  • Cover tightly with foil and bake for 40-50 minutes (depending on thickness of your chicken and peppers and your brand of quinoa), or until chicken is cooked through, veggies are crisp-tender, and quinoa is done (as shown in the photo in the article above, the quinoa will no longer look like tightly closed white dots but will instead be tender and you'll see lots of quinoa "tails").
    Two hands holding up finished casserole in white baking dish with Mexican toppings nearby.
  • Serve with desired toppings.
    Flatlay of baked recipe on wooden board with toppings like cheese, avocado and sour cream all around it.

Notes

Salsa: We generally use a thick and chunky salsa for this recipe, but have also tested it with looser, less thick varieties. Either will work fine, so feel free to use whatever you have on hand. However, less chunky salsa will result in a runnier, looser casserole (which is still perfectly delicious). Either way, the casserole will thicken slightly upon standing.
Quinoa: If your quinoa is not pre-rinsed, then before you add it to the casserole, you will need to rinse it in a sieve, swishing it with your fingers until the water runs clear. We always look for pre-rinsed brands to save that step.
Chicken breasts or tenders: Even when using chicken tenders, we often still cut larger tenders in half lengthwise to create thinner, fajita-like strips with more surface area to be coated with the delicious fajita spices. If you’re in a hurry, though, you can use the tenders whole, although the meat won’t be as well coated in the spice mixture. Also, if using tenders, be sure that your butcher has done a good job removing the little white nub of tendon from the end of each tender. If not, you can cut that off. We generally find, however, that there’s no need to worry about removing the white wisp of tendon that extends all the way down through the tender, as it generally becomes unnoticeable after cooking.
Make-ahead tips: This casserole can be made completely ahead of time, and then portions can be reheated later as needed for quick meals or meal prep. The baked (and cooled) casserole will keep, covered, in the fridge for at least three days. Just be sure to reheat portions gently, so that you don’t overcook the chicken. We generally use the microwave, re-heating each portion just until warmed through, and then adding our toppings.

Nutrition

Serving: 1½ heaping cups (excluding toppings) | Calories: 314 | Fat: 6g | Saturated Fat: 1g | Trans Fat: 0g | Unsaturated Fat: 4g | Cholesterol: 48mg | Carbohydrates: 38g | Fiber: 9g | Sugar: 6g | Protein: 28g

* Nutrition information should be considered an estimate only, and may vary depending on your choice of ingredients or preparation. No guarantees are made regarding allergies or dietary needs. Always consult a physician or dietician for specific advice and questions.

Course: Main Dishes
Cuisine: American
Author: Two Healthy Kitchens LLC at www.TwoHealthyKitchens.com
Tried this recipe?We’d LOVE to hear … please leave a star-rating!
a serving of this casserole on a square white plate, with optional toppings in the background
Chicken Fajita Quinoa Bake (No Pre-Cooking!) {from Two Healthy Kitchens}
Chicken Fajita Quinoa Bake (No Pre-Cooking!) {from Two Healthy Kitchens}
Chicken Fajita Quinoa Bake (No Pre-Cooking!) {from Two Healthy Kitchens}
So easy! Simply mix the uncooked quinoa directly in a 9×13 baking pan along with your salsa, black beans and some chicken broth.
Chicken Fajita Quinoa Bake (No Pre-Cooking!) {from Two Healthy Kitchens}
The fajita strips just need a quick toss with the delicious Mexican spices, and they’re ready to nestle on top of the quinoa mixture for baking.
Chicken Fajita Quinoa Bake (No Pre-Cooking!) {from Two Healthy Kitchens}

73 thoughts on “Mexican Chicken Fajita Casserole”

    • Thanks so much! This is one of those recipes that turns plain-old-chicken into a party-for-your-tastebuds! A fiesta kind of party, to be exact! Hope you love it as much as we do! Thanks for stopping by! 😀 ~G&S

      Reply
    • Thanks, guys! Yeah – it’s seriously delicious! The gorgeous peppers and onions, along with the salsa and fajita seasonings … all the flavors of traditional fajitas in one super-easy casserole! Olé! 😀 ~G&S

      Reply
  1. I’m totally trying this tomorrow! I didn’t know it was possible to cook quinoa this way, but oh wow, it is such a brilliant idea!
    And the fajita combo? SO. GOOD. I really need to have this for dinner soon. It looks beyond incredible!

    Reply
    • Oh, Consuelo! We totally hope you do give this a try! You’re gonna looooove it (bet those brothers of yours do, too!). It really is such an awesome, time-saving way to cook quinoa – we’re already working the method into other recipes we can’t wait to share! Happy weekend, friend! 😀 ~G&S

      Reply
    • Yeah, that no pre-cooking thing is so awesome! Who needs extra steps on busy evenings? And I totally hear ya on not reading a lot of poetry. Actually, since having kids, my poets of choice now include Shel Silverstein (as we know!), and also esteemed masters of verse such as Dr. Seuss and Jack Prelutsky! You know … kinda like my list of favorite movies began to include “Finding Nemo,” “Despicable Me” and “Hotel Transylvania”! 😀 ~Shelley

      Reply

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