Preheat your oven to 375°F (190°C).
Heat olive oil in a large skillet over medium heat. Sauté diced onion and garlic until soft.
Add ground beef and cook until browned. Drain excess grease.
Stir in cooked rice, diced tomatoes, tomato sauce, Italian seasoning, salt, and pepper.
Spoon the mixture evenly into the hollowed bell peppers and place them in a baking dish.
Cover with foil and bake for 30 minutes.
Uncover, sprinkle with cheese, and bake for another 10-15 minutes until cheese is melted and bubbly.
Serve warm and enjoy!