Telephone: 0033 389 718900
Address: Ilhaeusern

It began with the Haeberlin women drawing freshwater fish from the river Ill that ran beside the old house in Alsace, to be served up in the front room. 'My father, Paul, was the first male Haeberlin to cook here,' says Marc, the current head chef at the Auberge de L'Ill in the village of Ilhaeusern. 'Before him it was always the women.' When those matriarchs first opened a restaurant here in 1878 it was called L'Arbre Vert. As World War II drew to a close, a bomb aimed at the nearby bridge destroyed the old building, but the family was determined that the small matter of global conflict should not do away with 67 years of tradition. Paul Haeberlin and his brother Jean-Pierre rebuilt on the same site and decided to name the new restaurant after the fast- running river at its door. Paul won his first Michelin star in 1954. He won his second in 1962 and his third in 1967. The Auberge de L'Ill has held three Michelin stars continuously since then. Only one other restaurant - Paul Bocuse, just outside Lyon - has held three stars for longer. And even then, only for one more year. In a country which regards fine food not merely as a luxury but as a mark of civilisation, the Auberge de L'Ill is pretty much a national institution. Johnny Halliday has eaten here. It is as important as that.

Today the homely 'Auberge', originally built in the Alsatian farmhouse style, is a collection of solid, glossy buildings stretching along the banks of the river Ill. The sleek dining rooms, with their collection of modern art and their glasses designed exclusively by the sommelier, look out at a line of mature willows which, in turn, bend their heads towards the water in deference. There is substance and heft here, the accretion of years of experience of doing things the three-Michelin-star-way; which is to say, grandly, formally and with a vocabulary that excludes the word 'excess'. 'To be chef here is a responsibility,' says Marc Haeberlin, 'But it is a nice one.'

There was no moment when Marc Haeberlin officially took over from his father. He returned to the Auberge in 1976, after stages with Bocuse and Troisgros, and slowly took on more and more responsibility, until eventually he was running the 25-strong kitchen. 'But my father is still here in his whites,' Marc says. 'He is 79 now, but he is not going to retire. He needs to be in the kitchen.' This is a family business writ large. Marc's mother, Marie, is in the dining room, tending to the flowers. His sister Isabel does front of house, alongside their uncle, who tours the dining room at night. And Paul is always there in the kitchen at his son's side.

Sometimes, Marc says, they argue about new dishes. 'He always prefers more sauces, but we come to a gentlemen's agreement.' Haeberlin Senior's interest is understandable. At the heart of its huge, italicised menu is a set of dishes he created over 40 years ago and for which people still return: a famed mousse of frogs' legs, a terrine of foie gras with truffles, lobster 'Prince Vladimir', served with a champagne sauce.

Then there are the two headliners. Firstly, the salmon soufflé 'Auberge de L' Ill' - a rectangle of salmon fillet beneath a fluffy overcoat of beaten egg whites flavoured with pike and nutmeg, in a cream and Riesling sauce so rich it would probably be illegal in certain more puritanical countries. 'The recipe has not changed in 40 years,' says Marc. 'Only the size of the portion. It is smaller now.'

But the star is a whole black Perigord truffle, coated in foie gras and wrapped in pastry, then deep fried and served on a dark sauce of more black truffles. Yours for a mere 125 Euros (or £85). There are those who might regard this dish, in its boisterous marriage of technique and indulgence, as an obscenity; the gastronomic equivalent of the deep fried Mars bar. Perhaps, but just like the deep fried Mars bar, it has its fans. 'Some people, they come here and they order the truffle to start and then the truffle to follow,' says Michel, the Maitre d' these past 33 years. 'It is a lot of truffle.'

Indeed it is, this standard-bearer for a menu so feverishly rooted in French classicism that it would get laughed out the door if anybody attempted it in London. But, here, the execution is so acute, and the service so exquisite, that it works. As it should at these prices. The truffle is only the most expensive item on a menu that can make your eyes water. The cheapest starter is £20. Main courses average £26. But you do not discuss price at the Auberge de L'Ill. It is just not done. Dinner here can never cost less than £100 a head and anybody who books a table knows that. Curiously, the 850-strong wine list is much more approachable. It may contain bottles of P¿trus and d'Yquem from the very beginning of the last century, at prices in four figures of anybody's currency, but the list starts at a little over a tenner. It is also very, very French and heavy with pages of Alsatian Reislings and Gew¿rtztraminers. It is almost as if there is barely a vineyard anywhere else in the world. Of those 850 wines only 27 are from outside France. 'I would like to have more from elsewhere,' says Serge Dubs, the sommelier once ranked the best in the world, 'but my customers do not want it.'

These customers - who have included presidents Chirac and d'Estaing, the emperor of Japan, the King of Sweden and the Queen Mother, as well as Barbara Cartland and Bobby Charlton (though not together) - want the Auberge de L'Ill to be what it has always been. 'We have customers who come here and do not open the menu,' Marc Haeberlin says. 'They say, "Pate de Foie gras and Salmon soufflé". And that is it. We do encourage them to try new dishes, as we change much of the menu by the seasons.'

Do fashions in the restaurant world trouble him? He shrugs. 'You hear when a new restaurant opens - all about the cost of the architecture and the décor. But you can't eat the curtains.' What matters, he says, is not fripperies but fundamentals. It is an ethos which has served the Haeberlin family very well these past 124 years. Why should they change their act now?