Stroganoff - cooking recipe

Ingredients

1 medium sirloin steak, cut into bite-size pieces
1 medium onion, chopped
1 small can sliced mushrooms (optional)
1 stick margarine
1 (12 oz) container sour cream
1 (12 oz) bag of wide noodles

Preparation

While noodles are cooking, melt margarine in large skillet at low heat.