Boil water in a big pot. Submerge bell peppers for 2 minutes, remove from the boiling water and line them on a sheet pan.
Heat a skillet with oil, add the ground turkey, stir, cooked through. Season with dried basil, oregano, garlic powder, onion powder, salt, and pepper, stir to mix. Add the tomato paste, stir, simmer for a minute.
Preheat the oven to 350 degrees. Fill each bell pepper with cooked turkey mixture, layer the tomato, mushrooms, fresh mozzarella and Parmesan cheese on top.
Place the stuffed pepper in the oven for 15-20 minutes or until the cheeses are melted. Sprinkle with red pepper flakes. Enjoy while they're still hot!