Preheat your oven to 375°F (190°C).

Cut the tops off the bell peppers and remove the seeds. Place them upright in a baking dish.

Heat olive oil in a skillet over medium heat. Sauté finely chopped onion and minced garlic until the onion is translucent (about 3-4 minutes).

Add ground beef, breaking it up, and cook until browned (5-7 minutes).

Stir in cooked rice, tomato sauce, and drained diced tomatoes. Add Italian seasoning and salt & pepper to taste. Simmer for 5 minutes.

Stuff each pepper with the beef filling, packing gently but firmly.

Pour water into the baking dish to create steam, cover with foil, and bake for 35 minutes.

Remove foil, sprinkle cheese on top of each pepper, and bake uncovered for another 10-15 minutes until cheese is melted and golden.

Let cool for a few minutes, garnish with parsley, and serve warm.