Carefully slice the tops off the bell peppers, saving them for another use if desired. Remove the seeds and membranes to create enough space for stuffing. Stand the peppers upright in a baking dish, ensuring they fit snugly.
In a large skillet over medium heat, warm a splash of olive oil. Sauté the finely chopped onion until it becomes translucent and soft, about 3-4 minutes. Add the minced garlic and cook for an additional minute.
Increase the heat slightly and add the ground beef to the skillet. Sprinkle in the ground cumin, chili powder, smoked paprika, and season with salt and pepper. Cook, stirring frequently, until the beef is browned and thoroughly cooked, about 6-8 minutes.
Gently fold in the cooked rice and the drained diced tomatoes, mixing until everything is well incorporated. Remove the skillet from heat and taste the mixture, adjusting the seasoning if needed.
Using a spoon, fill each prepared bell pepper with the beef and rice mixture, pressing down gently to pack it in.
Generously sprinkle shredded cheese on top of each stuffed pepper.
Cover the baking dish with aluminum foil and bake in the preheated oven for 20 minutes. Remove the foil and continue baking for an additional 10-15 minutes, or until the cheese is melted and bubbly.
Once cooked, allow the stuffed peppers to cool slightly for about 5 minutes before serving.
Notes
Serve garnished with fresh cilantro or parsley and a dollop of sour cream or creamy avocado salsa for added richness.