A Jar Is Not a Garnish: Five Cornichon Suppers for a Hostile November

November in Britain has a particular talent for making dinner feel like admin. The sky is the colour of a closed laptop, the radiator is making a noise like a distant tuba, and by 4.15pm you are already wondering whether it is acceptable to eat standing up while staring into the fridge. It is. But you can do better, and you can do it with a jar.

Not just any jar. A jar of cornichons: small, firm, sour, crunching with the sort of moral clarity that a gherkin can only dream of. The French keep them in the door of the fridge the way other people keep hope. We should do the same. This is not a garnish situation. This is a strategy.

The doctrine, briefly

A cornichon is not there to decorate a plate. It is there to do work. It brings acid when something is too rich, salt when something is too quiet, and texture when something is, frankly, a bit wet. It makes a potato taste more potato-like. It cuts through cheese. It gives a fish finger a sense of purpose. It is the most French thing in your kitchen and it costs about two pounds.

The rules are simple. Buy small, firm cornichons, preferably labelled extra fins, and avoid anything sweet and floppy that has wandered in from a picnic hamper. Keep the brine. Use the brine. Do not buy a jar so large that it becomes a geological feature at the back of the fridge; buy a sensible jar and replace it when it empties. This is a relationship, not a collection.

Supper one: warm potatoes, smoked mackerel and too many cornichons

Boil new potatoes until tender. While they are still warm, dress them with Dijon mustard, a little olive oil, a squeeze of lemon and a generous spoonful of the cornichon brine. Fold through sliced cornichons, a chopped spring onion and flaked smoked mackerel. Add black pepper. Eat warm, with bread, if you have any, or without bread, if you are pretending to be disciplined.

This is the sort of dinner that looks like you had a thought. You did not. You had a jar.

Supper two: the Comté and cornichon toastie

Butter the outside of two slices of good bread with a mixture of soft butter and Dijon. Inside, layer grated Comté, sliced cornichons and, if you are feeling flush, a slice of ham. Griddle slowly, pressing gently, until the cheese is molten and the bread is crisp. Cut on the diagonal, because a diagonal toastie tastes more French than a rectangular one. This is not science, it is atmosphere.

The cornichons stop the cheese from becoming a warm duvet. They are the acid alarm clock. Serve with a few extra on the side, not as a garnish but as a reminder of what you are capable of.

Supper three: lentils, sausages and the brine trick

Brown some good sausages in a pan, then tip in a drained tin of lentils, a spoonful of Dijon, a splash of water and a handful of chopped cornichons. Let it bubble until the lentils are hot and the sausages are cooked through. Finish with parsley and a little more cornichon brine. The brine is the point: it seasons the lentils and makes the whole thing taste as if you knew what you were doing.

This serves two, or one person who has had a day and is not taking questions.

Supper four: rotisserie chicken with cornichon crème fraîche

Shred a supermarket rotisserie chicken. Mix crème fraîche with Dijon, lemon zest, chopped cornichons, a little tarragon if you have it, and black pepper. Fold the warm chicken through the cold cream, or serve the cream on the side if you are being polite. Jacket potatoes, rice, or simply a large pile of green beans will do.

The cornichons keep the crème fraîche from becoming a cloud of dairy optimism. They give it a spine. This is a ten-minute dinner that tastes like a bistro on a side street, provided you do not look too closely at the washing-up.

Supper five: fish fingers and cornichon tartare

Fish fingers are a British institution and should not be apologised for. Make a tartare with mayonnaise, chopped cornichons, capers, lemon juice, a little chopped shallot and plenty of black pepper. Cook the fish fingers until properly crisp. Serve with peas and the tartare, and perhaps a few extra cornichons on the plate because you are an adult and nobody can stop you.

The tartare is sharp, salty and ridiculous in the best way. It makes a freezer tea feel like a decision, rather than a surrender.

The brine clause

Do not pour the brine down the sink. It is a seasoning, not a by-product. A spoonful in a vinaigrette, a splash in potato salad, a little in the pan with lentils or a cheeky teaspoon in a martini if you are that sort of person. It keeps the doctrine alive between jars.

What to buy, and what to ignore

The supermarket shelf is full of impostors. Look for small, crunchy cornichons in a sharp, vinegary brine. Avoid sweet pickles, avoid anything enormous and rubbery, avoid the sad jar that has been open since a barbecue in July. In the UK, the decent ones are easy enough to find in most large supermarkets and delis. Buy two jars if you are planning a week of this. You will not regret it, and you will not have to go out in the dark again.

The cornichon is not a flourish. It is a commitment to dinner. November is long; the jar is small; the logic is sound. Open it.