In a large skilllet brown meat and onion until cooked through. Remove from skillet and set aside.
To the same skillet add beef broth, tomatoes, and pasta. Stir to coat pasta. Bring to a boil and reduce heat to medium. Cook uncovered for 15 minutes. Add zucchini, continue cooking for 5 to 10 minutes more.
Return meat to skillet, add parmesan cheese stir to reheat meat and melt cheese.