In a medium-sized bowl, combine hummus, 1/2 cup feta, and green onions.
Place a small bowl or drinking glass in the center of a large, round platter (the platter in our photos is this one, which is about 12.5 inches in diameter). If you plan to place a bowl of pita chips or veggies at the center of the finished wreath (as we did in some of our photos), you'll want to use that bowl (or a similarly sized glass), to be sure the hole in the middle of the wreath is the right size. Use a rubber scraper to spread the hummus mixture in a circle all around the bowl/glass you placed at the center (refer to the photos in our post to see how we did this). Remove the bowl/glass from the center using a gentle, upward twisting motion. If needed, you can carefully insert the tip of a toothpick under the edge of the bowl/glass to help it release.
In another small bowl, toss parsley, oil, and salt until the parsley is thoroughly coated and the oil and salt are evenly distributed. Spoon parsley mixture in a circle on top of the hummus layer, leaving a small border of hummus showing all around.
Place halved cherry tomatoes, cut-side down, randomly throughout the parsley layer, so they look like Christmas ornaments.
If making the optional bow out of red pepper, cut one broad, flat side off the pepper (as shown in the photo in our post), and gently but firmly press a metal, bow-shaped cookie cutter (we use this one) through the pepper slice to cut out your bow. Place the bow on your wreath.
Sprinkle entire wreath lightly with a dusting of 1 - 1 1/2 tablespoons very finely crumbled feta, to look like snow. You can adjust the exact amount of feta, depending on the diameter of your wreath – you want it to look like just a light dusting, without using so much feta that it hides the other ingredients.
Serve immediately with dippers of your choice, or cover and refrigerate for up to 1-2 days. (See make-ahead tips below.)
Make-ahead tips: You can make this recipe partially ahead by mixing together the ingredients for both the hummus layer and the parsley salad layer – cover and refrigerate them separately until finishing your wreath. Alternately, you can make the entire wreath completely ahead, up to 1-2 days before serving. Store the platter in the refrigerator, tightly covered in plastic wrap, but be sure the wrap doesn't stick to your wreath or smash it. Also, note that if you make the parsley layer ahead of time, it may soften and darken just a little, but it still looks nice and tastes great.