Budget Beef Stroganoff - cooking recipe

Ingredients

1 1/2 lbs chuck or 1 1/2 lbs round steaks
1 large onion, chopped
1/4 cup butter or 1/4 cup margarine
2 (10 1/2 ounce) cans cream of mushroom soup
water, 1/2 soup can
1 tablespoon cider vinegar
1 teaspoon ketchup
1 (4 ounce) can mushroom pieces (this was not in the original recipe but I think its a nice addition )

Preparation

Cut meat into very thin strips ( easier to do when meat is partly frozen ); set aside.
Melt 1/3 of the butter in a skillet. Saute onion and remove.
Add remaining butter to skillet and brown the meat.
Add onion and remaining ingredients to meat.
Mix well, cover and simmer 45 minutes to 1 hour.
Do not salt.
Serve over rice, noodles or toasted French bread.