Steps
1. Preheat your oven to 375°F (190°C).
2. Cut the top off the bell pepper and remove the seeds and membranes.
3. In a bowl, mix together the cooked quinoa, black beans, diced tomatoes, corn, onion, olive oil, cumin, chili powder, salt, and pepper.
4. Stuff the bell pepper with the quinoa mixture, pressing down gently to pack it in.
5. Place the stuffed pepper upright in a baking dish and cover it with foil.
6. Bake in the preheated oven for 25 minutes.
7. If using cheese, remove the foil and sprinkle cheese on top, then bake for an additional 5 minutes until the cheese is melted and bubbly.
8. Remove from the oven, let cool for a minute, and garnish with fresh cilantro before serving.