Cook until tender
   ¼  cup  Onion  [chopped]
   2  tbl  Margarine

 Stir in
   1  tbl  Flour
   ½  cup  Light cream
   1  can  Mushrooms  [3 oz, drained]
   ½  tsp  Salt
   ¼  tsp  Pepper

 Heat to boiling, stirring constantly.

 Remove from heat and stir in
   ½  cup  Sour Cream

 Heat.  Serve with fondue meat.