Cut beef strips 1 1/2" x 1 1/4".
Mix flour, salt and pepper. Coat beef with flour mixture.
Melt 1/3 of the butter in a large pan.
Add onions and saute until golden. Remove and set aside.
Melt 1/3 more of the butter; add mushrooms and sute 5 minutes. Remove and set aside.
Brown meat strips in remaining butter; add the bouillon, wine and onions.
Stir to dissolve bits on pan bottom. Simmer 20 minutes or utnil the meat is tender and mixture is thickened.
Add Worcestershire sauce, sour cream and mushrooms. Heat gently. Serve over rice or noodles.