Preheat your oven to 375°F (190°C) and grease a baking dish.
Cut the tops off the bell peppers and remove seeds. Set aside.
In a skillet, cook the ground meat with onions, salt, and pepper until browned. Stir in rice, marinara sauce, and Italian seasoning.
Spoon the mixture into the peppers, pressing lightly to fill them. Top each with Mozzarella and Parmesan.
Place the peppers in the baking dish, cover with foil, and bake for 25 minutes. Remove the foil and bake for an additional 10 minutes, or until the cheese is golden and bubbly.
Notes
Choose Your Colors: Red, yellow, and orange peppers are sweeter, while green peppers have a slightly bitter taste. Pick your favorite!
Make It Vegetarian: Swap the ground meat for sautéed mushrooms or lentils for a plant-based option.
Add Extra Flavor: Sprinkle fresh basil or parsley over the peppers before serving.