Cod Tongues with Black Butter Sauce

A short finishing recipe that assumes the tongues have already been blanched and that a batch of black butter sauce is standing by. Both assumptions need filling in for a modern cook.

• Do not let them boilCod tongues are gelatinous and collapse into shreds at a rolling boil. Bring the pan only to a bare steam, long enough to heat through — two or three minutes — then drain.
• What a cod tongue isNot a true tongue but the fleshy gelatinous flap of muscle from the underside of the jaw. It is sold fresh or frozen in Atlantic Canada and turns up in Nordic fish markets; elsewhere you may have to ask a fishmonger to order it, often alongside cod cheeks.
• Blanching, firstThe recipe presumes an earlier step, since it calls for tongues already blanched and for the liquid they were blanched in. The book does not give that step here; a gentle simmer in salted water or a light court bouillon until the tongues are firm and opaque will produce both the tongues and the small quantity of stock the recipe asks for.
• Half a gillA gill is a quarter-pint: 4 fl oz by US measure, 5 fl oz imperial. Half a gill is therefore somewhere between a quarter cup and a scant third of a cup — just enough liquid to keep the pan from scorching, not a poaching bath.
• Black butter sauceBeurre noir: butter cooked until the milk solids are deep brown and nutty, then finished off the heat with a splash of wine vinegar and, usually, capers and chopped parsley. Brown, not burnt — once it smells acrid it is bitter and must be started again.
• A pint of sauce is a banquet measureA pint (16 fl oz US, 20 imperial) of black butter over eighteen tongues is a great deal of sauce by modern eyes. Half a cup or so will coat them; increase it if you mean to send the rest to table separately.
• YieldEighteen tongues will serve about three as a first course, or two as a main course with potatoes.