Prepare noodles according to package directions, omitting salt and fat.
While noodles cook, cook meat, green onions and mushrooms in a large nonstick skillet until meat is browned, stirring until it crumbles; drain.
Return meat mixture to skillet; add gravy and next 3 ingredients, stirring well. Cook over medium heat 3 to 5 minutes or until thoroughly heated. Stir in sherry, if desired. Serve over drained noodles.