1. Preheat oven to 375°F (190°C).
2. Prepare bell peppers by cutting off tops and removing seeds and membranes.
3. Cook filling in a skillet: sauté onion and garlic, add ground meat, and stir in cooked rice, diced tomatoes, oregano, paprika, salt, and pepper.
4. Stuff bell peppers with filling and top with cheese.
5. Bake covered for 25 minutes, then uncovered for 10-15 minutes or until peppers are tender and cheese is bubbly.