1.Cook noodles according to package directions; keep warm. 2.Meanwhile stack beef steaks; cut lengthwise in 1/2 and then crosswise into 1" wide strips. In large nonstick skillet, heat 2 tsp oil over medium-high heat until hot. Add beef and garlic (1/2 at a time) and stir-fry 1 minute or until outside surface of beef is no longer pink. (Do not overcook) Remove from skillet; season with salt and pepper. 3.In same skillet, cook mushrooms in remaining 2 tsp oil 2 minutes or until tender, stirring occasionally. Remove skillet from heat. Add gravy mix and water; blend well. Return to heat; bring to a boil. Reduce heat to low; simmer 1 minute or until sauce is thickened, stirring frequently. Return beef; heat through. Serve over noodles; pass sour cream.