Preheat the oven to 375°F (190°C).
Prepare the bell peppers by cutting off the tops and removing seeds.
In a skillet, sauté the diced onion and garlic until translucent.
Add the ground beef or turkey to the skillet and cook until browned.
Stir in the cooked rice, diced tomatoes, Italian seasoning, salt, and pepper.
Stuff each bell pepper with the meat and rice mixture, and place them in a baking dish.
Top each pepper with shredded cheese.
Cover the baking dish with foil and bake for 30 minutes, then remove the foil for an additional 10-15 minutes.
Allow the peppers to cool for a few minutes before serving.