2 cups left over fish, picked over and freed of bones. 1 cup thin white sauce, dried bread crumbs buttered.
Butter a baking dish and line with crumbs. Add a layer of fish, using half, and cover with half the sauce. Cover with a layer of crumbs. Add another layer of fish, sauce, and crumbs, making this last layer of crumbs quite thick. Place in a hot oven and leave until crumbs are brown and fish is heated through.