Prepare fish quenelles. Poach them in a combination of the stock and clam juice. Put on plate ready to use. Take stock from heat. Pour cold oysters into the liquid. Stir to wash and warm oysters. Lift out oysters and place on plate with quenelles. Strain liquid through a damp cloth into a bowl, ready to use. There should be about 2cups. If not, add stock to make 2cups.
Melt butter in skillet. Stir in flour. Stir-cook for a couple of minutes. Add strained liquid, nutmeg, salt and pepper. Stir until thick. Add sherry, quenelles, and oysters. Make liaison of yolks and crème. Carefully stir into pan, being careful not to damage quenelles. Heat. When hot, spoon into coquilles (shells) or small baking dishes. Sprinkle with crumbs and then broil until tops are brown. Serve as a first course with French bread.