Creating Quinoa Stuffed Bell Peppers is simple if you follow these steps:

1. Preheat Oven: Preheat your oven to 375°F (190°C).
2. Prepare Peppers: Cut the tops off the bell peppers and remove the seeds and membranes. Set them aside.
3. Cook Quinoa: In a medium saucepan, combine quinoa and vegetable broth (or water). Bring to a boil, then reduce heat to low, cover, and simmer for about 15 minutes or until quinoa is fluffy and liquid is absorbed.
4. Sauté Vegetables: In a skillet, heat a tablespoon of oil over medium heat. Add diced onion and garlic, sautéing until the onion is translucent.
5. Mix Filling: In a large mixing bowl, combine the cooked quinoa, sautéed onion and garlic, black beans, corn, diced tomatoes, cumin, chili powder, salt, and pepper. Stir until well combined.
6. Stuff Peppers: Carefully spoon the quinoa mixture into each bell pepper, packing it down slightly. If using cheese, sprinkle a layer on top of the filling.
7. Arrange in Baking Dish: Place the stuffed peppers upright in a baking dish. Add a splash of water to the bottom of the dish to help steam the peppers as they bake.
8. Bake: Cover the dish with foil and bake in the preheated oven for 25-30 minutes. Remove the foil and bake for an additional 10 minutes to melt the cheese, if using.
9. Garnish: Once done, remove from the oven and let cool slightly. Garnish with fresh cilantro or parsley before serving.

These steps will guide you in creating this delicious and nutritious dish effortlessly.