Preheat oven to 350 F.
In a deep pan over medium heat, sauté ground turkey and diced onion in olive oil. Add a good amount of garlic powder and salt for flavor. Once turkey is fully cooked, add chopped cabbage. Stir to mix, cover, and cook for 5 minutes over medium heat.
Add diced tomatoes and pureed tomato sauce. Add a bit more salt. Mix in 1/2 half cup of Parmesan cheese.
Cover, reduce heat between low to medium, and cook for 25 minutes. Stir occasionally to prevent sauce from sticking to bottom of pan.
In a separate pot, follow instructions for 1 bag of boil-in-a-bag brown rice. Once cooked, set rice said.
Once the turkey mixture has finished cooking, add the cooked rice and stir to mix. Add most of remaining Parmesan cheese and stir. Cover mixture and cook on low for another 10 minutes.
Wash and cut the heads off the green peppers. Remove the pepper's innards. Place the peppers in a tray filled with 1/4 inch of water (prevents the bottoms from being burned).
Stuff each pepper to the top with the turkey mixture. Sprinkle the remaining Parmesan cheese on top.
Bake for 25 minutes. Add grated Italian cheeses to the top of each pepper. Cover and bake another 5 minutes to melt the cheese, or alternatively, broil.
Serve and enjoy!