Seasoned greetings:Salt meat early, vegetables late and fish delicately, says Skye Gyngell.

Correct seasoning is vital in cooking, making whatever produce you are using more vibrant. For this reason, salt is the most valuable tool in a store cupboard – although I don't think food should ever actually taste salty, which is why careful attention must be paid during the cooking process.

I always like to use sea salt, as it is more elegant and less abrasive than table salts, but salt can come in many different guises. In Asia, for example, they tend to season dishes with fish sauce (as with the chilli jam here), tamari or soy, and molluscs from the sea tend to have a salty flavour that requires nothing further.

Salt has always been a valuable commodity as it works as a preservative; such foods as cod, preserved lemons and Parma ham are all cured using salt. At the restaurant, we follow a principle of early salting, which means that all our meats are salted a couple of days before cooking. The salt first draws out the moisture and then returns deeply into the meat to create a beautiful flavour and succulence during the cooking. Fish should be only gently salted, as its flesh is so delicate.

Meanwhile, our vegetables are only salted during the cooking process – when blanching or boiling vegetables the water should be almost as salty as the sea – and then no further seasoning is needed. Potatoes need more salt than any other vegetable; spinach the least. Over-salting can be corrected by using a squeeze or two of lemon juice.

Skye Gyngell is head chef at Petersham Nurseries, Church Lane, Richmond, Surrey, tel: 020 8605 3627, www.petershamnurseries.com

Salted roast beef

This recipe works similar to a cure or as a simple brine – and you will not be disappointed with the results. The most important thing is to use a simple sea salt as opposed to a finer variety and not to re-salt the meat before cooking.

Serves 6-8

2kg/4lb beef fillet
2 tbsp sea salt (1 tbsp per kilo)
A little freshly ground pepper

Using a clean, slightly damp cloth, pat the meat dry and lay it on a clean chopping board. Do not remove any of the outside layer of fat, as this will add to the succulence and taste of the meat. Salt the meat and place in a container, covering the meat with a damp, clean cloth. Place in the fridge and allow the meat to cure for 24 hours.

To cook, set your oven to its maximum temperature, wipe the meat clean and season with a little pepper but no additional salt. Place in a pan and roast for no more than 5 minutes per kilo. So, in this case, roast the 2kg beef fillet for 10 minutes. Remove from the oven and leave in its pan, covering the meat loosely with foil. Allow to rest in a warm place for 20 minutes. Serve with whatever you choose – I serve it as simply as possible, with a little freshly grated horseradish folded through some crème fraîche and a drop or two of red-wine vinegar.

Roasted Dover sole with clams, marjoram and olive oil

Dover sole is one of the most beautiful fish to be found in the waters around Britain. Delicate and sweet, it is a great treat when roasted and served with sage butter and spinach or, as it is here, with clams and a gentle olive oil. It is the clams in this dish that provide the saltiness.

Serves 4

Allow one Dover sole per person – approximately 250g/8oz each (ask your fishmonger to prepare the fish for you)
A little sea salt and plenty of freshly ground pepper
2 tbsp mild extra-virgin olive oil
250g/8oz clams, rinsed of any grit with several changes of water
1 small bunch of marjoram, leaves only

Start by setting your oven at its maximum temperature. Season the fish with just a little salt and plenty of pepper and place in a roasting pan. When the oven is at its hottest, place the fish on the middle shelf and roast for 12-15 minutes. While the fish is roasting, place a pan over a high heat and add a tablespoon of olive oil. When the oil is hot, add the clams and some of the marjoram. Cover with a lid and cook for 3-4 minutes, shaking the pan a couple of times to help open the clams. Once all the clams are open, remove from the heat.

Take the fish from the oven and divide among four plates. Divide the clams among the plates, pour over the remaining olive oil and scatter with the remaining marjoram leaves. Serve piping hot.

Chilli jam

This is good with so many things – lamb, beef or just a grilled-cheese sandwich.

Makes about 4 jars

11/2kg/3lb roasted tomatoes
1 tbsp mustard seeds
150ml/5fl oz red-wine vinegar
75g/3oz fresh ginger, peeled, finely chopped
7 cloves of garlic, peeled, finely chopped
5 red chillies, deseeded, chopped
140g/41/2oz caster sugar
4 tbsp fish sauce

Place the tomatoes in a large saucepan. In a separate pan, toast the mustard seeds until they pop. Remove from the heat and grind with a pestle and mortar. Add the seeds and all the other ingredients to the tomatoes and cook over a very low heat for 2-3 hours, stirring every now and then. Remove from the hob and allow to cool before spooning into jars and placing in the fridge. You will now have a rich jam – sweet and sour, hot and slightly salty all at the same time.