Stuffed Pepper Casserole

pound extra-lean ground beef

small green peppers, coarsely chopped

onion powder

salt to taste, optional

garlic cloves, minced

long grain brown rice, cooked

jar of low-sodium spaghetti sauce (If you are using a plain spaghetti sauce, you will want to add in 1/4 tsp Italian seasoning, 2 tsp season salt, 2 tsp onion powder, and 1 1/2 tsp garlic powder to give more flavor.)

reduced-fat mozzarella cheese blend, divided