Preheat Oven: Heat to 375°F (190°C).
Prepare Peppers: Cut the tops off the peppers and remove seeds. Set them aside.
Cook Beef: Heat olive oil in a pan. Sauté onion and garlic until soft. Add ground beef and cook until browned.
Mix Filling: Stir in tomato sauce, cooked rice, Italian seasoning, salt, and pepper. Cook for 2 minutes.
Stuff Peppers: Fill peppers with the beef mixture. Place them in a baking dish.
Bake: Wrap with foil and bake for 30 minutes. Uncover, top with cheese, and bake for 10 more minutes or until cheese melts.
Serve: Let cool for 5 minutes and serve warm.