1. Preheat oven to 350 degrees F.
2. Cut out stem ends of bell peppers and discard. Scoop out seeds. Bring 8 cups water to a boil in a large pot and blanch the peppers (1 minute). Drain and cool under cold running water. Set aside.
3. Heat oil in a large skillet over medium heat. Add onion and garlic and stir until softened (3 minutes). Add turkey and brown (4-5 minutes). Drain and discard the fat.
4. Transfer the turkey mixture to a medium bowl and mix in rice, 1/2 cup tomato sauce, parsley, salt, and pepper. Stuff the peppers with the mixture and place them in a 2-quart casserole dish. Spoon the remaining 1/2 cup tomato sauce over the peppers. Cover and bake until the peppers are tender and the filling is heated through (30-35 minutes).