- 1 pound beef tenderloin
- 1 tsp grated onion
- ½ pound mushrooms
- 1 ½ tbsp. butter
- 1 tbsp flour
- ¾ cup soup stock
- ½ tsp prepared mustard
- ¼ cup sour cream
- Salt and pepper
- 1 ½ tbsp butter
- ½ tsp grated onion
- Remove all fat and skin from meat then cut into strips.
- Sprinkle lightly with salt and pepper then let it stand at room temperature for an hour.
- Cook onion and mushrooms in butter until lightly browned then sprinkle with flour and mix thoroughly then stir in soup stock, mustard, and sour cream.
- Bring to boil then season sauce to taste with salt and pepper.
- Let it simmer for 10 minutes.
- Melt butter and quickly brown meat strips with onion.
- Add meat to sauce and cover and keep hot 20 minutes to blend the flavors.