Slice the tops off the bell peppers and remove the seeds and membranes. Set them aside.
In a large mixing bowl, combine the shredded chicken, BBQ sauce, cooked quinoa (or rice), corn, black beans, garlic powder, onion powder, salt, and pepper. Mix well until all ingredients are fully combined.
Stuff each bell pepper with the BBQ chicken mixture, pressing down gently to pack it in.
Place the stuffed peppers upright in a baking dish. If they don't stand well, you can trim the bottom slightly for balance.
Cover the dish with aluminum foil and bake in the preheated oven for 25 minutes.
Remove the foil, sprinkle shredded cheddar cheese on top of each pepper, and return to the oven for an additional 10 minutes, or until the cheese is bubbly and slightly golden.
Once done, remove from the oven and let them cool for a few minutes. Garnish with fresh cilantro before serving.
Notes
Feel free to customize the ingredients based on your preferences.