Tartar Sauce

An ingredient list only, and a short one: vinegar, lemon, salt, Worcestershire and a third of a cup of butter. Treat it as a warm butter sauce for fried or broiled fish rather than the cold, mayonnaise-bound tartar sauce sold today.

• What this is notThere is no mayonnaise, egg yolk, pickle, caper, onion or parsley here, all of which define modern tartar sauce. Cooks expecting the thick cold relish will be surprised; this is a thin, sharp, buttery dressing.
• Butter measureOne-third cup of butter is about 5 1/3 tablespoons, or roughly 75 g, a little over two and a half ounces.
• Keep the heat lowWith this little liquid to a third of a cup of butter, the sauce holds only if the butter is melted gently and the acid whisked in off direct heat. Boiling it will split the fat out and leave a greasy pool.
• Worcestershire proportionA full tablespoon of Worcestershire is assertive by modern palates, and brands vary considerably in salt and anchovy. Taste before adding the quarter teaspoon of salt, which may not be needed at all.
• Acid balanceA tablespoon of vinegar plus a teaspoon of lemon juice makes a sharp sauce of the kind suited to plain fried fish. Cider or white wine vinegar suits it; distilled white vinegar makes it harsh.
• Yield and servingRoughly a scant half cup; the recipe gives no yield. Spoon it over at the table rather than holding it warm, as it will separate if it sits.