Cook beef, onions, pepper, salt, garlic, and bell peppers in a skillet. Cook until beef is browned. While beef is cooking, cook pasta according to package directions.Drain. In a greased 13X9 baking dish, place half of the pasta. Top with half the beef, top with 1 jar sauce. Top with 4 slices provolone. Top with half the sour cream. Repeat layers. Top with mozzarella. Bake at 350 for 30 minutes. Sprinkle with parmesan, and bake 10 more minutes.