Beef Stroganoff - cooking recipe

Ingredients

1 to 1 1/2 lb. beef tenderloin
butter or margarine
1 large onion, minced
1/2 lb. mushrooms, sliced
2 tsp. dry mustard
1 tsp. salt
1/4 tsp. pepper
beef broth
1 Tbsp. all-purpose flour
1 c. sour cream

Preparation

About 45 minutes before serving:
On a cutting board, trim fat from tenderloin.
Cut meat across the grain into 1/2-inch slices. Cut each slice into 1/2-inch cubes.
Dry strips well on paper towels.
In a 10-inch skillet over high heat, in 1 tablespoon hot butter or margarine (be careful not to let it burn), cook half of meat, stirring constantly, until lightly browned or about 1 minute (meat will be rare).
Pour meat and drippings into a medium bowl and set aside.