Preheat the oven to 400 degrees F. Fill a 9×13-inch baking dish with 1/2 inch of water.
Trim 1/4 inch off the top of each bell pepper, then scoop out and discard the stem, ribs and seeds. Place the peppers cut-side down in the baking dish, cover with foil, and bake for 20 minutes. Remove foil, set the peppers aside to cool, then drain the water from the pan.
While the peppers are cooking, heat the olive oil in a saucepan or Dutch oven set over medium heat. Add the onions and cook, stirring occasionally, until translucent, approximately 3 minutes. Add the ground turkey and cook until browned, breaking the meat apart while stirring, about 5-7 minutes. Stir in the garlic and cook for 60 seconds, until fragrant.
Stir in the drained tomatoes, Italian seasoning, crushed red pepper, rice, and half the cheese. Season with salt and pepper to taste.
Wipe out the baking dish and lightly grease it with olive oil. Place the peppers cut-side up in the pan, then divide the turkey mixture evenly between the peppers, pressing the mixture down to pack in the filling in as much as possible. Top each pepper with the remaining Monterey Jack cheese, then bake for an additional 15-20 minutes, or until peppers are tender.
Sprinkle with parsley and serve.