- Stir together ingredients for sauce in a small bowl. Set aside.
- Preheat oven to 400ºF and cut bell peppers in half lengthwise. Remove seeds. Place bell peppers on a baking sheet lined with parchment paper or an oven safe baking dish, cut side down. Bake for 15 minutes.
- While peppers bake, heat a large nonstick skillet over medium heat and add ground turkey. Brown for 6-7 minutes, using a spatula to break up turkey into small crumbles. Drain any liquid from pan and return to stove. Add mushrooms, onion, and carrots. Cook 5 minutes longer. Add brown rice. Stir sauce once more and pour into skillet. Cook for 4-5 minutes longer. Turn heat off.
- Turn bell peppers over using tongs. Spoon turkey mixture into bell peppers, overfilling them slightly. Sprinkle with panko and spray with cooking oil spray. Return to oven for 12-15 minutes longer, until panko is toasted. Serve hot, topped with cilantro.