SALT, simple sodium chloride, is a remarkable substance, but it has been given a rotten time by the health pundits. No doubt they are right that we eat more than we need and possibly more than is good for us, particularly if we like heavily salted snacks such as crisps. None the less, our bodies do need some salt to function at full tilt. Besides, food tastes so dismally lacklustre without it. An unreasonable terror of the saltcellar is one of this decade's least appealing contributions to gastronomy.

Salt highlights and enhances the flavours of savoury foods and even sweet ones - a pinch or two of salt in a cake batter vastly improves it without being detectable - in a way no other ingredient can, and that is just the most obvious of its uses. Its value as a preservative has long been recognised: a hygroscopic mineral, when sprinkled on foods it draws water out of them.

Human beings have always liked salt. Throughout history it has been a valued commodity, gathered in one form or another right across the world since the earliest times. Salt production has changed little over the centuries. Technical refinements may have made it more efficient, but the fundamentals remain the same.

Rock salt, deposited by ancient seas long since dried up, can be mined like any other mineral, but the more common industrial method is to pump water through salt layers to form a brine that is evaporated in heated open pans or, for the purer variety, in vacuum-pans.

Sea salt is the product of natural evaporation. Sea water is concentrated in basins until its minerals begin to be deposited, when it is moved to other basins where extraneous calcium is deposited. In the third set of basins, called the 'crystallisers', the sodium chloride begins to form and can be harvested.

Unrefined sea salt is also naturally evaporated. It is never absolutely pure, but is all the better for that. The traces of other minerals, which vary with the location, are what distinguishes one raw sea salt from another.

I often bring back bags of sel gris from France, where it is sold in most greengrocers. As the name suggests, it is a pale grey, coarse crystal, slightly damp (it clogs salt mills and tends to cake). But what makes it special is its distinct flavour: far more complex than mere saltiness.

I have traces of the salt snob in me - I do prefer coarse sea salt as a seasoning - but I try to keep it in check. After all, the main point of salt is its saltiness, and fine-ground table salt is more than adequate and extremely convenient. But it is not as pure as you might imagine: it is usually adulterated with additives that keep it free-flowing but make it a bad bet for pickling, though they do not affect it much otherwise.

Cucumber & Pepper Pickles

Dry salting the vegetables for pickles draws out much of their water (after 24 hours they will be sitting in their own brine) but leaves them crisp.

Ingredients: 2 cucumbers, peeled

2 green peppers, deseeded and cut into strips

4oz (110g) coarse salt

1 1/2 pts (855ml) cider or white wine vinegar

7oz (200g) caster sugar

6 sprigs fresh dill

3 cloves garlic, halved

1 1/2 tsp black peppercorns

8 allspice berries

Preparation: Cut the cucumbers into four pieces, then quarter each lengthwise. Layer with the peppers and salt in a bowl. Weight down with a large plate, cover with a tea towel and leave for 24 hours. Drain, rinse well, then drain completely again. Pack into cold sterilised jars.

While the vegetables are salting, make the flavoured vinegar by bringing all the remaining ingredients slowly to the boil. Draw off the heat and leave for three hours, then strain.

Pour the cold flavoured vinegar over the vegetables in their jars, making sure they are completely covered. Seal tightly with non-corrosive lids. Leave for at least a week to mature.

The Lancashire way to boil potatoes

This recipe comes from Lindsey Bareham's In Praise of the Potato (Grafton Books). Though it may seem an unnecessarily complicated way to go about boiling potatoes, the end result is more than worth the effort. The potatoes are salty, slightly browned, slightly mushy and very buttery.

Serves 4

Ingredients: 2lb (900g) potatoes

coarse or fine salt

4oz (110g) butter

Preparation: Peel the potatoes, cut into even-sized pieces and soak in very salty water (about 1 1/2 oz/40g salt dissolved in each pint) for two hours. Drain and put the potatoes into a pan with equally salty water to cover. Boil, and when nearly done add a little cold water to lower the temperature and make the potatoes floury.

Drain and return to the pan, cover with a folded cloth and complete the cooking over a low heat. Lumps of potato will stick to the pan: scrape these off and mix with the rest of the potatoes. The scorched flavour is essential. Once they are done, dot with butter and serve.

Chicken in a Salt Brick

This is not an everyday way of cooking chicken, but great fun for an occasional treat. Though the chicken is entirely embedded in salt, the flesh does not, as you might expect, become unbearably salty, but stays marvellously moist and tender. You will have to trust me on the timing - there is no way to check to see if it is done, other than cracking open the salt block.

You will need a good deal of salt for this dish. Quite how much you will need depends on the size of casserole in relation to the bird. To milk the last drop of drama out of this cooking method, crack open the salt brick at the dinner table.

Serves 4-6

Ingredients: 4lb (1.8kg) free range chicken

4-6lb (1.8-2.7kg) coarse salt

Preparation: Make sure the chicken is tightly trussed so that no salt can get into the cavity. Find a casserole large enough to take the chicken with a good half-inch (1cm) or more gap all around. Line with a double layer of silver foil, leaving enough trailing over to cover the top eventually.

Spread a half-inch (1cm) thick layer of salt on the base, and sit the chicken on top of it. Pour more salt around the chicken, making sure that there are no air-pockets and that it is well packed down. Continue adding salt until the chicken is completely covered and enclosed, mounding it up well over the top so there is a generous layer covering the upper part. Sprinkle with 2tbs water, then seal tightly in the foil.

Bake at 230C/450F/gas 8 for 1 3/4 hours. Turn off the oven and leave to rest for 10 minutes. To serve, lift the package on to a dish and unwrap to reveal the salt brick. Smash it with a hammer or mallet, brush the salt from the skin and transfer to a serving dish to carve as normal.

To cook a whole fish in a salt brick, the method is exactly the same - only the timing differs. You need to allow 30 minutes for a 1-1 1/2 lb (450-675g) fish, 50 minutes for a 2lb (900g) fish.

Chinese Salt and

Pepper Walnut Brittle

Adding salt and pepper to a nut brittle may sound an odd notion, but do not let that put you off. The succession of sweet, salt and spiced heat is superb.

Makes 1lb

Ingredients: 8oz (225g) walnuts

8oz (225g) caster sugar

6tbs water

1 level tsp fine salt

1 level tsp freshly ground black pepper

Preparation: Spread the walnuts out on a baking sheet and place in the oven set to 150C/ 300F/gas 2 to warm through and dry out. Oil a marble slab or a baking sheet. Place the sugar and water in a heavy-bottomed pan and stir over a moderate heat until sugar dissolves to give a clear syrup.

Brush down any crystals stuck on the side of the pan with a pastry brush dipped in hot water, and stop stirring. Bring to the boil and cook until the syrup turns a rich caramel brown (approximately 170C/338F but colour is the best guide).

Draw off the heat and immediately tip in the walnuts, salt and pepper. Stir quickly to mix evenly, and pour on to the oiled marble or baking sheet. Spread out as well as you can and leave to cool completely. Break up into pieces.