Partially freeze steak; trim fat from steak. Slice steak diagonally across grain into 1/4-inch-wide strips. Coat a nonstick skillet with cooking spray; place over medium-high heat until hot. Add steak; cook 3 minutes or until steak strips are browned on both sides. Remove from skillet. Drain and pat dry with paper towels. Wipe drippings from skillet with a paper towel.
Coat skillet with cooking spray; place over medium-high heat until hot. Return steak to skillet. Add mushrooms, onion, and garlic; saute 3 minutes. Add beef broth and next 4 ingredients; bring to a boil. Cover, reduce heat, and simmer 45 minutes or until meat is tender. Remove from heat; stir in sour cream. Spoon over noodles; sprinkle with parsley.