Crayfish Etouffee

2 1/2 lbs. crawfish tails
1/4 lb. margarine
3 large onions chopped finely
1 tbsp. parsley chopped
salt and pepper to taste

Saute onions in margarine about 15 min. until soft. Add crawfish fat from body cavity and cook over low heat, stirring until fat comes to the top. Add tail meat season to taste. Add just enough hot water to Etouffee for desired consistency. Simmer 20 minutes, add parsley. Serve over hot rice.