Tartar Sauce

The ingredient column has been scrambled by the original typesetting; read it as 1 cup mayonnaise, 1 teaspoon onion juice, 1 tablespoon chopped cucumber pickle, 1 tablespoon capers. Everything else is a matter of seasoning and temperature.

• The hinge: make the base sharperThe instruction to make the mayonnaise "rather more sour and with a little more mustard than for salad" is the whole point of the recipe. Fried fish is rich and bland, and a salad-strength mayonnaise disappears against it. With commercial mayonnaise, work in about a teaspoon of lemon juice or cider vinegar and a half teaspoon of Dijon or dry English mustard per cup, then taste.
• Onion juiceA period technique: grate an onion on the fine side of a box grater and press the pulp through a sieve, or halve an onion and scrape the cut face with a spoon. It gives sharpness without wet chopped onion loosening the sauce. A teaspoon is roughly what a quarter of a medium onion yields.
• Cucumber pickleIn this period this almost certainly means a sour cucumber pickle rather than sweet gherkins or bread-and-butter slices; the recipe does not say so outright, but the direction to make the base sourer points that way. Cornichons or a plain dill pickle are the closest match. Chop fine and blot on a towel so the brine does not thin the sauce.
• CapersBrine-packed capers should be drained and roughly chopped; salt-packed ones need a rinse and a soak first, or the sauce will be too salty once the pickle goes in.
• "Set on the ice"The icebox instruction. Refrigerate for at least half an hour before serving so the onion and pickle flavours come forward, and use within three or four days.
• Thickness"Quite thick when served" means the sauce should hold a spoon mark. If the pickle has watered it down, fold in another spoonful or two of mayonnaise rather than trying to correct it with more seasoning.
• If you make the mayonnaise yourselfThe original assumes a hand-made mayonnaise built on raw yolks, which is never heated at any stage. Use pasteurised eggs if you are serving anyone elderly, pregnant, very young or immunocompromised.
• YieldAbout a cup, enough for six servings of fried or grilled fish.