Cook pasta according to package directions. Meanwhile, in a large skillet, cook the beef, mushrooms and green pepper over medium heat until meat is no longer pink; drain. Add the tomato puree, pepperoni, sugar and seasonings; cook and stir for 5 minutes.
Drain pasta; stir into meat mixture. Heat through. Sprinkle with cheese. Remove from the heat; cover and let stand until cheese is melted. Yield: 4 servings.