Food & Drink: Heaven in a half-shell

THE QUESTION of food as an aphrodisiac will get its annual airing as St Valentine's day approaches. But is there really such a thing as the food of love? Many are the substances ascribed certain powers, from figs and pomegranates to Spanish fly (tincture of the cantharides beetle), truffles and certainly seafood such as lobster. But the most contemporary concept to fit the bill must be a candle-lit supper of oysters with caviar and a bottle of vintage champagne in the ice-bucket. It's a combination that works on nearly all the senses with suggestive undertones in appearance, smell, texture and taste.

The prospect of an oyster supper will not appeal to all, though. Custom requires that we eat them raw, in all their naked purity, served by the half-dozen or dozen on their hollow half-shells. They should come on a bed of crushed ice with no more relish than quartered lemons and perhaps a shake of Tabasco, and some thinly-sliced, buttered brown bread on the side. If you were in France you'd be offered a little saucer of shallot-infused vinegar. But the idea of sliding a mollusc down the throat demands a certain kind of bravado. And why do we need to eat oysters raw, anyway?

It was the great chef Auguste Escoffier, when he ruled the kitchens of the Savoy Hotel at the beginning of the century, who popularised the cult of raw oysters (and what would a plat de fruits de mer in France be without their presence?). But in other centuries, all the way back to Roman times, we have enjoyed our oysters cooked. In the Roman cookery book credited to Apicius, there is a recipe for oysters simmered in their own juices with lovage, the celery-tasting leaf. The liquid from cooking the oysters was made into a sauce thickened with ground almonds. Sounds delicious. A similar recipe is found in one of the first English cookery books: oysters simmered with a seasoning of ground mace and ginger, and sweetened with sugar.

The best cooked oysters I have ever eaten were at a six-course oyster feast prepared by the Dorchester Hotel chef, a Swiss by the name of Willi Elsener. He is a cook who brings to his European training some skilful refinements from culinary travels in the Far East. Once you have tasted his treats, you really wonder why you'd ever eat oysters raw again. Would he share his recipes with us? Of course.

But first things first. Did Willi think oysters were an aphrodisiac? "Casanova ate 40 oysters every night before he went out to meet his girlfriends," says Willi helpfully. "I have only ever eaten 39, and they had no effect whatsoever. I can't say what would have happened if I had eaten the 40th."

We are in his elegant chef's office in the brightly-lit basement kitchens of the hotel, which he designed himself when he took over 11 years ago. His team of 120 chefs in spotless whites are bustling like bees, but there's no clamour or shouting or noisy clanging of pans. This is as civilised as a hotel kitchen gets.

The oyster, explains Willi, is the most sensitive thing, demanding your most careful attention. As an apprentice he used to open a 100 a day, a difficult skill to master - not only in avoiding injury to yourself, but also damage to the oyster. He will show me how later.

But first, the secret of cooking them. The oyster is mostly protein, and like white of egg which is also protein, it gets harder the longer you cook it. Rule number one: cook an oyster for no longer than it takes to stiffen up, not really more than 10 seconds in gently simmering liquid, when the edges start to curl.

You can cook oysters in their own liquid, basically the sea water retained in the shell, together with some white wine or champagne, and perhaps cream. Or fry them in a hot non-stick pan with a moistening of butter for 10 seconds or so, turning once. Or wrap inside a thin sliver of streaky bacon, and grill under fierce heat till bacon crisps, or dress it in a vest of blanched spinach leaf or tuck it in a parcel of blanched lettuce. One of the classic cooked oyster dishes is Oysters Rockefeller, the oysters sitting on a puree of watercress with a creamy sauce spiked with Pernod.

Willi's recipes (see right) include the most classic version: the poached oyster returned to its shell in a champagne cream sauce with caviar heaped on top. His own inventions include a sauteed quartet of oysters on a crab cake spiced with ginger; a dish of oysters and scallops served on a puree of potato, spiked with cooked celeriac; and oysters deep-fried in a light, crispy tempura batter.

There are two kinds of oysters sold in Britain and, this being The Dorchester, Willi is using the costlier, fatter, more expensive, superior natives - so-called because this large, smooth, round variety (ostrea edulis) has been native to the British Isles. (In Europe's grand hotels, Willi tells me, it's usually called the imperial.)

The other variety, ostreas gigas, is now generally known as the rock oyster. It is a pretty thing, with a wavy, thin, frilly shell. It could never grow here because our waters were too cold for it to reproduce, but this has been overcome and oyster farms in the West of Ireland and Scotland grow the seed in warmed inland ponds until strong enough to transfer to the sea shores.

The rock oyster matures in two to three years compared with four to five years for the native, and is accordingly much cheaper. The predominant oyster on the British market, it outsells the native by, oh, 99 to one.

Oysters are increasingly easy to obtain from fishmongers here (or by mail order, see panel), but we have a long way to go to catch up with the French, who have extensive beds in the Channel, on the Atlantic coast and in the Mediterranean to provide the billion oysters they consume each year.

Are we perhaps inhibited by the fact we can't open them? "You can do it," promises Willi confidently. He nestles the round base of a big, fat native in his hand, the flat lid uppermost, and points to a fingernail- sized slot at the base. This indicates where you need to force the short, blunt oyster-knife blade, the hinge. It's a tough, connective ligament and the knack, says Willi, is to push in the blade, and twist a quarter turn to exert leverage. When it gives, you've won. Then slip in a sharp knife blade above the flesh of the oyster and sever the soft muscle which attaches it to the top shell. This done, you can now lift off the top shell.

The exposed oyster, sitting in a pool of liquid in its hollow shell, is easy to detach. Slip the blade underneath and sever the muscle which links it to the lower shell. Brush away any little bits of broken shell.

Finding the way into a rock oyster is less easy. There is a tool on the market, shaped like a pair of pliers, one of the prongs extended to make a blade. Instead of looking for the oyster's secret entrance you attack it from the other end, smashing the delicate rim with the pliers. This opens up a route to the top muscle which can now be severed with the blade. This is crude but effective. Indeed, your tool box should reveal several weapons for reducing the frail end of the shell to rubble.

There is another way. Put them in a microwave and give them a 20-second blast. They will open far enough for you to push in a knife to prise away the top muscle.

Willi Elsener suggests you simply ask your fishmonger - he will have The Knack. Ask him just to force the hinges so they retain their liquid. When you get them home you can finish the job, severing the muscles easily enough. Then all you need to do is cook them.

CLASSIC OYSTERS WITH CHAMPAGNE AND CAVIAR

Serves 2

12 oysters, removed from their shells. Pour the liquid into a saucepan and retain the deep shell of each oyster

10g caviar

For the sauce:

1 teaspoon unsalted butter

14 shallot, finely chopped

2 tablespoons white wine

2 tablespoons dry champagne

100ml/4fl oz fish stock

100ml/4fl oz double cream

salt, rock salt, freshly ground pepper

1 egg yolk

1 tablespoon whipped cream

dill

Put grill on to a high setting. Prepare a bed of rock salt on a suitable serving dish. Press the shells gently on to the bed of rock salt, making sure that all the shells are level. Set aside.

For the sauce, sweat the shallot in the butter until the shallot is translucent, but without colour. Add the white wine and champagne and bring to the boil, then simmer to reduce until half the quantity remains.

Add the fish stock, return to the boil and simmer to reduce to half the quantity again. Add the cream and boil until a creamy consistency is obtained. Pass the sauce through a sieve into a clean saucepan and keep aside.

Heat the liquid from the oysters in a small saucepan. Make sure there is enough liquid to poach the oysters - if necessary, add one to two tablespoons of fish stock to it - and bring the liquid to the boil. Remove the saucepan from the heat and add the oysters. Cover the saucepan with a lid and leave for two minutes.

Remove the oysters with a slotted spoon and place one oyster back in each shell. Retain the liquid.

Using a saucepan, bring the liquid from the oysters to the boil and then simmer until about 1 tbsp remains. Add this to the prepared sauce. Bring the sauce back to the boil and season with salt and pepper. Remove completely from the heat and whisk in the egg yolk and whipped cream. Mix thoroughly and then pour over the oysters in equal quantities.

Place the oysters under the grill until a light golden brown in colour. Remove them from the grill and then garnish each oyster with caviar and dill and serve immediately.

SWEET CHICORY AND OYSTER SOUP INFUSED WITH ORANGE AND FENNEL VINEGAR

Serves 2

6 oysters, removed from the shells. Retain the liquid

1 tablespoon vegetable oil

1 heart of Belgian endive (stalks removed), roughly chopped

25g/1oz unsalted butter

25g/1oz caster sugar

50ml/2fl oz orange and fennel vinegar

100ml/4fl oz white wine

200ml/8fl oz fish stock

150ml/6fl oz double cream

salt, freshly ground pepper

Heat the oil in a small non-stick pan, add the endive pieces and sweat until translucent but without colouring. Remove onto a plate and keep aside.

Melt the butter in a saucepan, add the sugar and caramelise gently until golden brown, then add the strained oyster liquid and vinegar. Bring to the boil until the sugar is dissolved. Add the white wine and fish stock. Bring to the boil, and reduce to half the quantity. Add the cream, bring to the boil and allow to simmer until a creamy consistency is obtained.

To finish, put three oysters in each soup cup and add the endive pieces. Bring the soup to the boil. Then using a small hand blender, froth up the mixture until foamy and light. Adjust the seasoning as necessary. Pour the mixture into the soup cups to serve.

SCALLOPS AND OYSTERS ON CELERIAC AND POTATO PUREE

Serves 2

1 tablespoon vegetable oil

4 fresh scallops, without any roe, and cut in half lengthways

4 fresh oysters, removed from the shells (retain the liquid)

For the mashed potato:

75g/3oz celeriac, peeled and cut into small thumb sized cubes

2 (about 200g/7oz in total) medium sized red potatoes (such as Desiree)

25g/1oz butter, cut into small cubes

25ml/1fl oz single cream

salt, freshly ground white pepper

nutmeg to season

For the sauce:

1 teaspoon unsalted butter

12 shallot, peeled and chopped

100ml/4fl oz fish stock

50ml/2fl oz dry white wine

100ml/4fl oz double cream

1 egg yolk

1 pinch English mustard

1 tablespoon whipped cream

salt, freshly ground pepper

Put the grill on to a high setting. To make the celeriac and potato puree, first peel the potatoes, cut into chunks and place in a cooking pot together with the celeriac chunks. Cover with salted water, bring to the boil and simmer covered, (or steam in a steamer) until cooked. Drain in a colander and leave for two to three minutes to allow the remaining liquid to evaporate, then press through a potato ricer into a large saucepan. Place over low heat and, using a wooden spoon, mix in the butter cubes one by one.

Heat the cream separately and add to the potato mixture. Finally, season with salt, freshly ground pepper and a touch of nutmeg. Remove the saucepan from the heat, cover closely with buttered paper and keep warm.

While the potatoes are cooking, start preparing the sauce as follows: sweat the shallots in the butter until translucent, but without colour. Add the fish stock and white wine and bring to the boil. Simmer and reduce until half the original quantity is left and then add the cream and return to the boil. Allow to simmer until a creamy consistency is obtained and then pass through a sieve into a clean saucepan. Keep aside.

Pat dry the scallops and oysters. Heat a non-stick pan, add the vegetable oil and then pan fry the scallops and oysters on both sides. Remove the oysters after a few seconds but leave the scallops in the pan until cooked, but still moist. Season with white pepper and remove from the pan and keep in a warm place.

Spoon the mashed celeriac and potato mixture in equal amounts onto two plates, and then place the scallops and oysters on top. Keep to one side.

Bring the sauce back to the boil, remove from the heat and add the mustard and whipped cream, followed by the egg yolk. Whisk through thoroughly. Season with salt and freshly ground pepper and then pour over the scallops and oysters.

Brown under the grill and serve.

As an optional garnish, place some deep-fried rocket in the centre of each plate before serving.

OYSTERS SERVED ON A POTATO AND CRABMEAT CAKE

Serves 2

6 oysters, removed from the shells

25g/1oz ginger root, peeled and cut into fine strips and blanched

200g/7oz potatoes (Maris Piper)

75g/3oz white crab meat

75ml/3fl oz clarified butter

salt, freshly ground pepper

To garnish:

2 sprigs dill

Cook the strips of ginger in boiling, salted water. Strain and put on to a paper towel and keep aside.

Grate the potatoes using a medium sized grater then put into a muslin cloth and press very hard to remove as much liquid as possible.

Combine the potato, crab meat and ginger and season with salt and pepper. Add a third of the clarified butter to the mixture. Form two round cakes of the same size from the mixture. Heat the remaining clarified butter in a non-stick pan, add the cakes and pan fry until golden brown in colour and thoroughly cooked. Then remove from the pan, place on a paper towel and keep warm. Pat dry the oysters and using the same pan, pan-fry them in the remaining clarified butter. Season and then remove from the pan. Keep in a warm place on paper towels, until ready to use.

Place one potato cake in the centre of each plate and put the oysters on top of the cake. Garnish with the dill.

CRISPY OYSTERS WITH MARINATED VEGETABLES

Serves 4

12 fresh oysters

2 medium sized courgettes, topped and tailed, cut into 2-3mm thick slices

4 small plum tomatoes, peeled and cut into 3mm thick slices

4 tablespoons olive oil

12 lime, juiced

salt and pepper

flour to dust the oysters

For the batter:

100g/4oz plain flour

112 tablespoons olive oil

150mls/5fl oz dry white wine

1 egg white

mixture of a few salad leaves eg frisee, curly endive

Mix together the olive oil and the lime juice and then season with salt and pepper. Marinate the slices of courgette for about 30 minutes (retain the marinade for tossing with the salad leaves at the end).

Heat the olive oil in a non-stick pan and add the courgette slices. Fry quickly on both sides and then remove from the pan and drain on a paper kitchen towel. Allow to cool. Arrange the tomato and courgette slices alternately in a circle on each plate and keep aside.

For the batter, mix the flour with the oil, then add the white wine and continue mixing until all the lumps disappear. Whisk the egg white until stiff and fold it gently, but thoroughly, into the mixture. Season with salt and freshly ground white pepper.

Just before serving, cook the oysters. Heat the oil in a deep fat fryer or saucepan to about 180C/350F. Pat dry the oysters with a paper towel and dust with the flour.

Using a wooden skewer gently pierce each oyster and dip into the batter mixture. Allow any excess batter to run off, then drop each oyster into the hot oil. Deep fry until golden brown and then remove and drain on a paper towel.

Toss the salad leaves in the remaining marinade and then season with the salt and pepper. Arrange the salad leaves in the centre of the tomato and courgette ring. Put the hot oysters on top of the salad and serve.