Preheat oven to 375 degrees F.
Make the filling: Heat about 1 tablespoon of olive oil in a large deep skillet over medium high heat. Cook the ground turkey until fully cooked. Push it to one side of the skillet. Add a few more drizzles of olive oil and stir in the diced onions and minced garlic. Cook for 1-2 minutes until fragrant, and mix it back with the ground turkey. Add the Italian seasoning, canned diced tomatoes (drained), and cooked rice. Mix evenly. Season with salt and pepper to taste. Stir in the chopped parsley and ½ cup of the mozzarella cheese.
Cut each pepper in half, from top to bottom. Remove the seeds. You can also remove the stems, if desired. Drizzle the inside of the peppers with a little bit of olive oil and sprinkle with a few pinches of salt and pepper. It doesn’t have to be precise.
Fill the peppers with the prepared filling evenly. Arrange them on a 9x13 baking dish (filling side up). Add a little bit of water to the bottom of the pan, about ¼ cup. The water will allow the peppers to steam and become tender as they cook. Cover the pan tightly with aluminum foil.
Bake, covered, for 30 minutes.
Uncover, and top the peppers with the remaining cheese mozzarella and the parmesan cheese. Return to the oven (uncovered) and bake for another 10-12 minutes until melted. Broil for 1-2 minutes until golden brown on top.
Garnish with parsley. Serve immediately. Enjoy!