Heat oven to 375°F; lightly grease dish large enough to stand peppers upright.
Heat oil in large skillet over medium; sauté onion 3-4 minutes until softened, then garlic another minute.
Thoroughly mix turkey, rice, tomatoes, ¾ cup cheese, cooked onion and garlic, Italian seasoning, salt, and pepper in large bowl.
Stand peppers in dish; divide filling evenly, packing gently.
Cover with foil; bake 25 minutes.
Uncover; top with remaining cheese. Bake uncovered 10 minutes more until peppers tender and cheese melted and bubbling.
Cool 5 minutes; optionally garnish with parsley and serve.