Cook and stir ground beef and onion in a large pot until beef is no longer pink, about 10 minutes. Drain excess grease. Pour tomato sauce and tomato paste into the pot; season with pepper. Stir in tomato puree and ketchup. Add brown sugar, mustard, celery salt, onion salt, and garlic salt, stirring after each addition. Simmer sauce over medium-low heat, stirring frequently, until flavors combine, 30 to 45 minutes. Sprinkle in Parmesan cheese during the last 5 minutes of cooking.