In a large saucepan over medium-high heat, cook sausage and mushrooms until meat is brown. Drain.
Stir in broth, water, tomato paste, and Italian seasoning. Bring to a boil. Add spaghetti a little at a time, stirring constantly. Return to boiling; reduce heat. Boil gently, uncovered, for 14 to 17 minutes, stirring regularly, or until spaghetti is tender. Season with salt, pepper, and Parmesan.
You can also make this pasta with ground beef instead.