In a large skillet over medium-high heat, cook mushrooms and onions in butter until tender. Add garlic; cook 1 minute longer. Remove with a slotted spoon and keep warm.
Stir in flour to remaining liquid until no lumps remain. Add broth, Worcestershire sauce, vinegar, bouillon, salt and pepper; bring to a boil. Cook and stir for 2 minutes or until thickened. Stir in sour cream, thyme and reserved mushroom mixture; heat through (do not boil). Serve with noodles. Garnish with paprika and parsley.