In a large bowl, toss the strips of onion and peppers with 1 tablespoon oil, making sure the vegetables are all evenly coated with oil. Sprinkle 4 teaspoons of the spice blend over the vegetables.
Divide the vegetables onto two large, parchment-lined baking sheets, spreading the veggies out so they're not piled on top of each other. Roast vegetables for 7-8 minutes.