Two Small Jars, a Great Deal of Flavour

Every British kitchen has, somewhere near the back of a cupboard, a tin of mustard powder and a bottle of malt vinegar that gets used twice a year on chips. That is a waste. Between them, English mustard and the two vinegars I keep closest to the hob — malt and cider — can sharpen, thicken and lift a whole week of cooking for pennies. They are not garnishes. They are seasoning in the same league as salt, and once you treat them that way you need far less of everything else: less stock, less wine, less of the expensive bits that promise depth and deliver very little.

Getting the Best Out of English Mustard

Mustard powder is a volatile thing. The heat you want comes from a reaction that needs cold water and a little patience. Mix the powder with an equal volume of cold water, leave it ten minutes, and it will be fiercer than if you had stirred it straight into hot liquid. Heat stops that reaction dead, which is why a spoonful thrown into a boiling pan tastes of little more than dust.

So make a paste first, then add it. A teaspoon of powder and a teaspoon of cold water, rested, will season a cheese sauce for four, a pan of devilled kidneys, or a bowl of dressing with real authority. For a mustard sauce to spoon over gammon, whisk the rested paste into a white sauce with a splash of the ham's cooking liquid, then finish with a knob of butter off the heat. It should be sharp enough to make you blink once.

A word on the ready-made jar: it is a fine thing and I use it constantly, but it is milder and often sweeter. When a recipe wants bite, powder is your friend.

Malt and Cider Vinegar: Two Different Jobs

They are not interchangeable, though both are cheap and both are British to the bone.

• Malt vinegar is robust, slightly sweet and dark. It is for chips, pickled onions, piccalilli and chutneys, and for any braise where you want a malty bass note. It stands up to long cooking and to fat.
• Cider vinegar is brighter and fruitier, with a gentler edge. It belongs in dressings, with pork and apples, in slaws, and anywhere you want sharpness without shouting.

Keep both by the hob. If a stew tastes flat, it is more often short of acid than short of salt, and a tablespoon of malt vinegar at the end will do more than another stock cube ever could.

Dressings and Cold Sauces

A vinaigrette is the fastest place to practise. Three parts oil to one part cider vinegar, a teaspoon of mustard paste, a pinch of salt and a grind of pepper. Shake it in a jar. The mustard does two jobs: it flavours, and it holds the emulsion together so the dressing clings to leaves instead of pooling in the bottom of the bowl.

• Add a crushed garlic clove and leave it an hour for a sharper, more savoury dressing.
• Swap half the oil for double cream and you have a quick mustard cream for cold roast beef.
• Stir mustard paste and cider vinegar into mayonnaise with chopped tarragon for tartare sauce.
• Whisk mustard, cider vinegar and a spoon of honey into a glaze for roast ham, brushed on in the last twenty minutes.

Sharpening a Braise

Long cooking dulls everything. A braise that has bubbled for two hours at 150C will taste round and soft and, quite often, a bit tired. Acid brings it back to life.

Brown your meat, soften the onions and carrots, then add a tablespoon of mustard paste and two of malt vinegar straight into the pan and let it cook out for a minute before the liquid goes in. That minute cooks off the raw edge and leaves a savoury background note you cannot quite identify but would miss immediately.

Then taste again at the end. If it is heavy, add cider vinegar a teaspoon at a time. If it is thin and dull, malt. Do this before you reach for salt. Beef shin, shoulder of pork, a pan of braised leeks — all of them benefit. If the sauce is still loose, take the lid off and reduce it hard for ten minutes; the flavour concentrates as the water goes.

Everyday Uses Worth Keeping in Your Head

• Cheese on toast: mustard paste in the butter, a splash of cider vinegar in the cheese.
• Roast potatoes: a teaspoon of mustard powder stirred into the fat.
• Gravy: a little mustard paste whisked in at the end, plus a few drops of vinegar.
• Greens: a splash of cider vinegar over drained cabbage lifts it no end.
• Soup: malt vinegar with lentil or split pea, cider with tomato or beetroot.
• Fridge pickles: equal parts malt vinegar and water, a teaspoon each of salt and sugar, sliced onion or cucumber, an hour in the jar.

None of this costs much. A tin of mustard powder and two bottles of vinegar will set you back less than a single supermarket ready meal, and they will outlast it by months. Start with a dressing tonight, and by the weekend you will be reaching for them without thinking.