In a large saucepan cook the ground beef, fresh mushrooms (if using), onion, and garlic until meat is brown and onion is tender. Drain.
Stir in the canned mushrooms (if using), broth, water, tomato paste, Italian seasoning, and pepper. Bring to boiling. Add the broken spaghetti, a little at a time, stirring constantly. Return to boiling; reduce heat. Boil gently, uncovered, for 17 to 20 minutes or until spaghetti is tender and sauce is desired consistency, stirring frequently. Serve with Parmesan cheese. Makes 4 servings.