Return the meat and onions to the heat and add the garlic. Cook for 1 minute. Stir in the beef broth, chili seasoning, diced tomatoes with the juice, and tomato sauce. Bring to a boil, then reduce to a simmer. Stir in the uncooked pasta. Cover and cook, stirring occasionally, until the onions and pasta are tender. Add salt and pepper to taste. When ready to serve add the cheese. Stir until melted.