Another Fish Sandwich

A leftover-fish spread of the kind that filled tea sandwiches when Monday's boiled cod was a fixture. The proportions are given per cup of flaked fish, so it scales to whatever you have.

• White sauce means bechamelA medium white sauce here is about 1 tablespoon butter, 1 tablespoon flour and 1/2 cup milk, cooked until it coats the spoon and cooled before mixing in; use less milk if you want it stiffer. Heavy cream can be used straight, as the recipe allows, but the sauce version tends to hold together better and is less likely to weep into the bread.
• How much to moistenStart with 2 tablespoons of sauce or cream per cup of fish and add more only until the mixture just clings. Too wet and the filling soaks through white bread within minutes.
• Flake, do not processPull the fish apart with a fork or press it in a mortar as directed. A food processor turns cooked white fish into paste and the sandwich loses all texture.
• Season it yourselfThe recipe assumes the fish was boiled in salted water. Taste and add salt, black pepper and lemon juice; a teaspoon of lemon does more for cold cod than the Worcestershire does.
• Which fishCod, haddock and any firm white fish work as written. Bluefish is oily and strong and needs more lemon; skip the Worcestershire with it. Poached fresh fillet, cooled, substitutes directly for the cold boiled fish.
• YieldOne cupful of flaked fish, roughly 5 to 6 oz cooked, makes filling for three or four sandwiches, or a dozen small crustless tea sandwiches cut in fingers.
• KeepingMix, chill and use within a day. Cooked fish bound with cream is a quick spoiler; keep it refrigerated until the sandwiches are cut, and do not hold made sandwiches at room temperature for hours.