Preheat your oven to 375°F (190°C). Lightly grease a baking dish large enough to hold the pepper halves.

Bring a small pot of salted water to a boil. Blanch the hollowed-out bell pepper halves in the boiling water for 3-4 minutes until slightly softened. Remove and set aside to drain and cool slightly.

In a large skillet over medium heat, brown the ground turkey until no longer pink. Drain off any excess fat. Add the diced onion, zucchini, and carrots, cooking until softened, about 5-7 minutes.

Stir in the cooked brown rice, drained diced tomatoes, tomato sauce, oregano, basil, salt, and pepper into the skillet. Cook for 5 minutes, stirring occasionally, until heated through and well combined.

Carefully spoon the meat and rice mixture evenly into each bell pepper half. Arrange the stuffed peppers snugly in the prepared baking dish. You can add about 1/4 inch of water to the bottom of the dish to prevent sticking.

Cover the baking dish with aluminum foil and bake for 30 minutes. Remove the foil, sprinkle the tops with cheese (if using), and bake uncovered for an additional 10-15 minutes, or until the peppers are tender and the cheese is melted and bubbly.

Let the peppers rest for 5 minutes before serving hot.