Preheat Oven: Preheat your oven to 375°F (190°C).

Prepare the Peppers: Cut the tops off the bell peppers and remove the seeds and membranes. Place them in a baking dish.

Cook the Filling: In a large skillet, heat olive oil over medium heat. Add diced onion and garlic, sauté until fragrant. Add ground beef or turkey, cook until browned. Stir in diced tomatoes, cooked rice, oregano, salt, and pepper. Cook until the mixture is well combined and heated through.

Stuff the Peppers: Fill each bell pepper with the meat and rice mixture. Press down lightly to pack the filling. Top each stuffed pepper with shredded cheese.

Bake: Cover the baking dish with foil and bake for 30 minutes. Remove the foil and bake for an additional 10-15 minutes, or until the cheese is bubbly and golden brown.

Garnish and Serve: Remove from oven, let cool slightly, then garnish with fresh parsley and halved cherry tomatoes if desired.