2 lbs top round steak, sliced thin across the grain
1 lb fresh mushrooms, sliced
1 medium onion, sliced
1/4 tsp thyme
3/4 cup dry sherry
3/4 cup beef broth (Swansons)
3/4 tsp dry mustard
1/4 tsp garlic salt
Put all this in the crockpot, stir well and cook on low for 8 hours. Turn heat to high and mix 1-1/2 cup sour cream 1/2 cup Wondra flour, cake flour works too, heat on high for 40 minutes.
Serve over rice or noodles.