This recipe is very close to beef stroganoff that requires sour cream instead of whipping cream.
I usually make a double batch
1 1/4 pounds sirloin cut into 1/2″ cubes
3 T butter
1 T veg oil
1 clove garlic, minced or pressed
3/4 lb fresh mushrooms, sliced
1/3 C beef broth or water
1/3 C dry red wine
1 1/2 t soy sauce
2 t dijon style mustard
1 t cornstarch
1/2 C whipping cream
Brown the meat in 2 T of the butter and oil and the garlic. When done, remove to covered casserole in preheated 275° oven.
With remaining butter, cook mushrooms until soft. Add to meat and cook for 1 hour.
Meanwhile, add broth, wine, and soy sauce to pan. Stir up brownings until reduced to a glaze. Blend the mustard, cornstarch and cream and add to pan. Boil until thick and smooth. blend with meat until heated through.
Serve with egg noodles
I add cornstarch as needed to make thick sauce. 1/4 C with 1/4 C water will thicken nicely.
I normally use an entire blue container of mushroom per 1 1/2 pound of sirloin.
If the meat is cooked longer, it will be more tender. A different cut of meat will require longer cooking time.