Bring water to a boil in medium saucepan. Add noodles; cook 6 to 8 minutes or until tender. Do not drain.
Meanwhile, in medium skillet, cook ground beef and garlic-pepper blend over medium heat for 8 to 10 minutes or until beef is browned and thoroughly cooked. Drain.
To noodles in saucepan, add cooked ground beef, gravy, mushrooms and sour cream; cook until thoroughly heated. If desired, sprinkle individual servings with chopped fresh parsley.