Heat oven to 400°F. Lightly oil a medium nonstick skillet and place on medium heat. Add onion, garlic, salt and pepper (to taste),and parsley. Sauté until onions start to soften and become translucent, be sure not to burn garlic, add ground turkey and sprinkle with garlic powder. Cook until meat starts to brown up a little and make sure the turkey is completely cooked through. Add 1/4 cup of marinara and 1/2 cup of chicken broth, mix well and simmer on low for about 5 minutes until it starts to reduce and thicken. Combine cooked rice and meat together. Cut the bell peppers in half lengthwise, and remove all seeds. Spoon 2/3 cup meat mixture into each pepper half and place in a 9 x 13-inch baking dish. Top each pepper with a sprinkle of cheese. Pour the remainder of the chicken broth on the bottom of the pan. Cover tightly with aluminum foil and bake for about 45 minutes or until peppers become tender, remove foil and cook for an additional few minutes to brown the cheese on top. Carefully remove from oven and serve right away.