Wash & dry fish; dust with flour. Mix egg with milk. Dip fish into egg/milk mixture. Dredge in crumbs. Reserve. Heat butter in pan. Add 3 Tbls. Flour & stir into paste (roux). Cook 2 minutes. Add cream, stock & sherry. Simmer until thick. Add salt & shrimp. Simmer 5 minutes. Heat oil in skillet. Fry fish in oil for 1 1/2-2 minutes each side. Place on platter. Pour half the sauce over fish. Serve remainder separately.