Vegetarian

Preheat oven to 375°F and lightly grease a 9x13-inch baking dish.
Place bell pepper halves cut side up in the prepared dish and bake until slightly softened, 15–20 minutes.
Heat olive oil in a large skillet over medium heat, add diced onion and cook until softened, 3–4 minutes, then add minced garlic and cook 1 minute.
Stir in cooked quinoa, black beans, sweetcorn, diced tomatoes, cumin, chili powder, smoked paprika, salt, and pepper; cook until heated through, 5–7 minutes, then remove from heat and stir in 1 cup shredded Mexican cheese.
Remove the peppers from the oven and stuff each half with the quinoa and black bean mixture, then top with the remaining 1/2 cup shredded Mexican cheese.
Return the stuffed peppers to the oven and bake until the cheese is melted and the peppers are tender, 15–20 minutes.
Let the stuffed peppers cool 5 minutes, garnish with chopped cilantro, and serve.