Cook noodles according to package directions; Drain. Keep warm

Meanwhile stack beef steak; cut length -wise in half, then crosswise into 1 inch wide strips. Heat 2 teaspoons oil in large nonstick skillet over medium high heat until hot. Add 1/2 of beef and 1/2 of garlic; stir fry 1 minute or until outside surface of beef is no longer pink. Remove from skillet. Repeat with remaining beef and garlic. Season with salt and pepper.

Heat remaining 2 teaspoons oil in same skillet over medium high heat until hot. Add mushrooms; cook and stir 2 minutes or until tender. Remove from heat. Add gravy mix and water; stir to blend well. Return to heat; bring to a boil. Reduce heat; simmer 1 minute or until sauce is thickend, stirring frequently. Return the beef to skillet; heat through. Serve over noodles. Dress with sour cream.