In a large skillet, cook beef and onion over medium heat until meat is no longer pink; drain. Stir in the broth, pasta, water and seasonings. Bring to a boil. Reduce heat; cover and simmer for 15 minutes.
Add yellow pepper and zucchini; cover and cook 2-4 minutes longer or until pasta and vegetables are tender, stirring occasionally. Stir in tomatoes; sprinkle with cheese.