2 lg. onions
1/4 - 1/2 lb. mushrooms
1 pkg. au jus gravy mix
1/2 stick butter
1 c. sherry

Saute onions and mushrooms in butter until onions brown slightly. Add 1/4 cup sherry and au jus gravy mix (after mixing with a little water -- not the amount suggested on the gravy package). Let simmer until most of the liquid evaporates. Then add remaining sherry. Let simmer a few minutes.

Serve with London broil or roast beef.