2 tbsp. butter
1 lg. onion
1 lb. sliced roast beef (precooked)
1 (4 oz.) can sliced mushrooms
1 can condensed cream of mushroom soup
2 beef bouillon cubes
1 c. water
1 c. sour cream
1 (16 oz.) pkg. noodles

Melt butter in skillet. Saute onions and beef until tender (about 4 minutes). Stir in mushrooms, soup, water and add bouillon cubes. Cover and cook for 5 minutes. Blend in sour cream. Stir and cook until heated through on low heat for about 3 minutes. Serve over cooked noodles.