Food and Drink: Firm favourites from the ocean: Tuna and swordfish are rare and expensive, but when beautifully fresh and cooked to perfection they are among the most delicious of fish

TUNA fishing used to be big business around the north-western tip of Sicily. In early summer, huge shoals of tuna swam past the coast, and many villages and small towns had fleets of tuna boats. Now the shoals have dwindled and the fleets have all but disappeared, though evidence of past abundance remains in the solid tonnara buildings that housed the nets and other equipment. The island of Favignana, a few miles offshore from Trapani, is one of the last places where a tonnara and the characteristic flat-bottomed wooden boats are still in use.

The catch itself, the matanza, is a complicated and erratic affair, depending not only on the fish but also on currents, winds and weather. Only when all are in perfect harmony do the fishermen go out for the kill, a bloody and dramatic affair, definitely not for the squeamish.

This year, I am told, is a particularly bad one for tuna. Catches all around Europe are small, demand is heavy and prices have risen. The same goes for another of the big fish, the swordfish. This pushes them both into the luxury bracket, a rare treat to be cooked and savoured with respect.

Both tuna and swordfish should smell clean and fresh, as indeed should all fish. A noticeably fishy smell is a bad sign. Flesh should look juicy and bright; if it is drying out and tired, choose something else. Preserving the juiciness and tenderness is all- important. With tuna, this amounts to treating it like prime steak. If you have time, marinate for an hour or more with lemon juice, olive oil, salt, pepper and herbs. Then cook it by whatever method you please - barbecued, fried or seared, stewed, roasted.

An enticingly browned exterior and a meltingly tender pink interior are the ideal. I like it very pink with the flesh just heated through, but for some that may seem too radical. The important thing is to avoid ending up with a dehydrated slab that is a dull grey-fawn right through.

Swordfish has perplexed me for some time. In Italy or Portugal it is nearly always excellent, but when I have cooked it at home it has often been tough and dry. The fault, I am relieved to discover, has not been mine. Much of the swordfish sold here has either been frozen or imported in vacuum packs. Both processes damage the structure of the fish and, though it may look and smell fine, the end result is likely to prove disappointing. Truly fresh swordfish, whizzed in on ice, most probably from around the Mediterranean, is the only sort worth eating.

Even so, swordfish needs more attention than tuna. Marinating is essential for barbecuing or frying - only when it is to be cooked in a damp environment (such as a sauce) should you risk using it as it is. Unlike tuna, it should be just - but only just - cooked right through, bearing in mind that it will continue cooking in its own heat after it is removed from the pan. Swordfish a la rose, the trendy term for fish cooked rare to medium-rare, is not recommended. Nor for that matter is overdone swordfish.

Don't let these strictures put you off altogether. When it is good, swordfish is one of the most delicious of fish: meaty enough to satisfy hearty eaters, relatively free of fiddly bones, the veal of the sea.

Fresh Tuna Salad Nicoise

Usually made with tinned tuna, salad nicoise is even nicer with fresh. All the elements can be prepared in advance, but don't put the salad together until the last possible moment.

Serves 4 as a main course

Ingredients: 1lb (450g) tuna steak,

3/4 -1in thick

olive oil

12oz (340g) small new potatoes, boiled

4oz (110g) green beans, topped and tailed and cut in half

8 leaves cos lettuce, torn up

3 hard-boiled eggs, quartered

8oz (225g) cherry tomatoes, halved

8 tinned or marinated anchovy fillets

12-16 black olives

For the vinaigrette: 1tbs white wine vinegar

generous 1/2 tsp Dijon mustard

pinch of sugar

6tbs olive oil

salt and pepper

1tbs chopped chives

Preparation: Brush the tuna with oil and fry or grill it, making sure it is still pink at the centre, though not too rare. Make the vinaigrette in the usual way. If necessary, skin and bone the cooked tuna. Cut into large chunks and toss in a little of the dressing, then leave to cool.

Slice the potatoes thickly, unless they are tiddlers, then toss in a little more of the dressing and leave to cool. Boil the green beans for 3-4 minutes until al dente, drain, run under the cold tap, drain again and mix with the potatoes. Place remaining dressing in the bottom of a large salad bowl and cross the servers over it. Just before serving, compile the salad, starting with lettuce and adding all the other ingredients, mixing lightly with your fingers as you do. Finish with anchovies and olives. Toss at the table.

Seared Tuna with Warm Tomato and Anchovy Salsa

Searing tuna (cooking it briefly on a frighteningly hot surface) really enhances its flavour. Add a zippy raw tomato salsa, salted with anchovies, and you have one of the best tuna dishes.

Serves 4

Ingredients: 1 1/2 -2lb (675-900g) tuna steaks, about 3/4 in thick

juice of half a lemon

6fl oz (175ml) olive oil

2 cloves garlic, chopped

6 tinned anchovy fillets, roughly chopped

2 tomatoes, deseeded and diced small

2tbs chopped parsley

salt and pepper

Preparation: Cut the tuna into four portions and marinate with the lemon juice, 4tbs olive oil, salt and pepper, for at least half an hour. Begin the sauce while you wait. Warm the remaining oil in a small saucepan and add the anchovy and garlic. Cook over a low heat, mashing in the anchovy with a fork until it has melted and the garlic is lightly browned. Draw off the heat.

To cook the tuna, grease a heavy-based frying pan with a little oil, then set over a high heat for about 5 minutes until searingly hot. Shake excess marinade from the tuna and slap the pieces on to the hot metal (you may have to do this in two batches). Leave for 1 1/2 minutes, then turn over and give the other side another 1 1/2 minutes. With a sharp knife, check the interior which should be rosy pink. If it is still too raw for your liking, reduce the heat and cook a little longer.

As soon as the tuna is done, transfer to a warm serving dish and keep warm. Add tomato dice and parsley to the anchovy sauce, reheat it briefly and spoon it over the tuna. Serve immediately.

Roast swordfish

Here is one swordfish recipe where you can get away without marinating. The joint of fish is larded with garlic and roasted whole, frequently basted with white wine to keep it moist.

Serves 4-6

Ingredients: 2lb (900g) piece of swordfish

2 cloves garlic, cut into long slivers

1oz (30g) butter

5fl oz (150ml) white wine

1 large sprig thyme

1 sprig rosemary

salt and pepper

Preparation: Skin the swordfish but leave in one piece. Make small slits all over and push in slivers of garlic. Place in a shallow, lightly buttered baking dish. Pour over the white wine, tuck the thyme and rosemary alongside, season with salt and pepper and dot with butter.

Roast at 190C/375F/gas 5, basting frequently, for 20-35 minutes until just cooked. Exact timing will depend on thickness; my joint was about 3in thick and took 25 minutes. Take it hot to the table and carve.

Swordfish with Mozzarella and Mint

If there are just a few of you to feed, this is a good way to deal with swordfish. I have made it both with mint and sage leaves, and I cannot decide which I like better.

Ingredients (per person): 1 swordfish steak weighing 6-8oz, about 3/4 in thick

1/2 tbs lemon juice

1tbs olive oil

3 sage or mint leaves

2-3 thin slices of mozzarella

salt and pepper

1 wedge lemon to serve

Preparation: Lay steak in a dish and season with salt and pepper. Whisk lemon juice with olive oil and brush generously over fish. Leave to marinate for at least half an hour.

Grill the steak, fairly close to the heat, for about 2 minutes on each side, until almost cooked - do not overdo it. Lay sage/mint leaves on steak and cover with mozzarella. Season again with salt and pepper and grill until mozzarella is lightly browned and melting. Eat immediately.