Stir remaining 1/2 cup broth into flour; stir into beef mixture. Add onion mixture; heat to boiling, stirring constantly. Boil and stir 1 minute. Stir in sour cream; heat until hot (do not boil). Serve over noodles.
Wolf'em adaptation: Cook Wolf'em cups. Add 1 spoonful of egg noodles into Wolf'em cup. Add heaping spoonful of Stroganoff sauce over the noodles. Top with parmesan cheese and green onions.