Cut beef into 1/8-in. thick strips. In a large skillet over medium-high heat, cook beef in butter until no longer pink. Remove with a slotted spoon and keep warm.
In pan juices, cook mushrooms and onion until tender. Add garlic; cook 1 minute longer. Stir in flour. Add water, lemon juice, vinegar, bouillon, salt and pepper; bring to a boil. Cook and stir for 2 minutes or until thickened. Stir in sour cream and beef; heat through (do not boil). Serve with noodles. Garnish with paprika and parsley.