I just made my version of this dish tonight and it turned out really good!
I cut up a 1.5LB Sirloin Steak into small strips and browned it in 3Tbls of butter.
I chopped 1 medium onion and 3 cloves of garlic and after removing the browned beef from the skillet added the onion to the remaining butter sauce. Cooked for about 5 minutes then added the chopped garlic. Cooked another 5 minutes.
Added 8 oz sliced mushrooms, 1 cup white wine, 4 oz sweet vermouth, 1 tsp thyme, 1/2 tsp tarragon, 1 beef bullion cube, 1Tbls of Worcestershire sauce, Salt, Pepper, & 1 Tbs of Parsley.
Cooked about 8 minutes.
Added about 1 cup of sour cream. brought back to a boil then stirred in a shook up mixture of 2 oz of white wine and 2 oz of flour to thicken.
Simmered for 5 min then served over white rice --- Yummy!!!!