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, combine cooked quinoa, black beans, diced tomatoes, cumin, chili powder, salt, and pepper.
4. Stuff the bell pepper with the quinoa mixture, packing it lightly.
5. Place the stuffed pepper upright in a baking dish and sprinkle cheese on top if using.
6. Bake for 25-30 minutes, until the pepper is tender.
7. Remove from the oven and let it cool slightly. Garnish with fresh cilantro before serving.