Fish in Champagne

1 package frozen flounder fillets
1 grated onion
2 tablespoons butter or margarine
4 egg yolks
6 tablespoons light table cream
3 cups dry champagne
Parsley flakes

Melt butter in large skillet. Cook fish, onions and 1/2 cup of the champagne until fish is lightly browned. Remove fish and onions from skillet and keep warm.

In separate bowl combine egg yolks and cream. Add to champagne in skillet. Stir over low heat. Add remaining 2 1/2 cups champagne. Sauce will thicken slightly. Pour over fish and onions. Sprinkle with parsley flakes to serve.