Preheat your oven to 375°F (190°C).
Cut the tops off the bell peppers and remove the seeds.
In a skillet, sauté the chopped onion and minced 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.
Place the stuffed peppers upright in a baking dish.
Cover the dish with aluminum foil and bake for 30 minutes.
Remove the foil, sprinkle cheese on top, and bake for an additional 10 minutes until the cheese is melted.
Garnish with fresh parsley before serving.