Preheat the oven to 350 degrees. Wash hands with warm water and soap. Rinse the bell peppers, seed and cut in half. Place each bell pepper cut-side down on a large baking sheet and bake in the oven for 10 minutes. Wash and chop the zucchini.

Peel and chop the onion and heat some cooking oil in a large skillet over medium heat. Once the skillet is hot, cook the ground turkey and onion until the meat is browned, and drain the fat from the skillet. Add the garlic, zucchini, and mushrooms to the skillet and saute until the veggies are tender.

Remove the skillet from heat and add 1 cup of tomato sauce to the mixture, stir to combine. Add salt and pepper, if desired.

Arrange the bell peppers in a medium-sized baking dish and spoon the mixture into each pepper. Spoon remaining tomato sauce over the bell peppers to keep them from drying out. Bake in the oven for 20 minutes at 350 degrees.

Cover the bell peppers with cheese and bake for another 10 minutes, until the cheese is melted. 1 serving = 1 stuffed pepper. Refrigerate leftovers within 2 hours.