Cut the tops off the bell peppers and remove the seeds and membranes. If necessary, slice a small amount off the bottom to help them stand. Place the peppers upright in a baking dish.
In a large mixing bowl, combine the cooked quinoa, black beans, corn, diced tomatoes, cumin, chili powder, garlic powder, salt, and pepper. Mix well until all ingredients are combined.
Stuff each bell pepper generously with the quinoa filling, pressing down gently to pack it in.
Top each stuffed pepper with a sprinkle of shredded cheese.
Cover the baking dish with aluminum foil and bake in the preheated oven for 25 minutes.
After 25 minutes, remove the foil and bake for an additional 10-15 minutes until the cheese is melted and bubbly, and the peppers are tender.
Once done, remove from the oven, and let them cool for a few minutes.
Notes
Serve garnished with fresh cilantro and a drizzle of lime juice for extra flavor.