Ironically, my first encounter with the Taruschios was a scolding. Four and a half years ago I asked them, and nine other chefs, to contribute a restaurant review to this paper. Instead they offered, and we published, a plainly written broadside against restaurant critics. They condemned our breezy ignorance; we pretended, they said, to knowledge we did not possess. We were, they pointed out, toying fatuously with the roots of culture itself.
Several months later, it was the Taruschios' wine merchant, an enormous and ebullient man called Bill Baker, of Reid Wines in Bristol, who first took me to the Walnut Tree. His capacity for wine far outstretches mine, and the Taruschios watched bemused as, at the end of our interview, I weaved unsteadily from their bar, knocking over a few glasses on the way.
Inebriated though I was, I had managed to notice a thing or two. The Walnut Tree Inn was that rare thing: a pub serving restaurant- quality food. Moreover, it was spotless, its flagstone floors, half-panelled walls, white paintwork all immaculate. The waitresses were jolly, and efficient with it. It emerges that they are like family: the longest-serving has been there 29 years.
And what food] I had seen bresaola (beef marinated in highly spiced wine then air-dried) listed on the menus of Bibendum and Alastair Little, two of London's best and most fashionable restaurants. It was the Taruschios who popularised it in Britain, having come across it in a restaurant in the Jewish quarter of Rome; and here in the Walnut Tree was the version that had inspired the young chefs - served in paper-thin slices with olive oil, lemon, pepper and chives.
Nine months after interviewing Bill Baker, I returned to the Walnut Tree, this time to interview the Taruschios themselves. I found a couple, then married 27 years, still vividly in love and devoted to their Thai daughter, Pavinee. It was for Pavinee, adopted as a baby 17 years ago, that Franco first started cooking with oriental ingredients.
On to the Walnut Tree menu went cold Cornish lobster served with Thai sauce: a piquant mixture of nam pla (fish sauce), mild chilli, lemon grass and finely julienned kaffir lime leaf. A signature dish is Thai pork appetiser: minced pork with peanuts, garlic, coriander, shallots and sugar, served in a sturdy lettuce shell. This anticipated by more than a decade the London vogue for Thai ingredients.
These are far from the only dishes the Taruschios have popularised. The most recent is a lavish wild mushroom lasagne with parma ham, parmesan, porcini and truffles; called vincisgrassi it is a recipe from Franco's home region, the Marche, famed for its mushrooms and truffles. During a visit to Italy, the Taruschios found the recipe through a friend who collects old cookery books. Ann translated it from an 18th-century text, Il Cuoco Maceratese, by Antonio Nebbia.
The Taruschios are in two minds about the vogues rippling from their kitchen in rural Wales to chic London dining rooms. Chefs, they are convinced, risk cheating themselves by subscribing to trends rather than evolving their own styles from a local and personal base. However, they acknowledge that they, too, borrowed and learnt from their mentors. A great influence was Elizabeth David, whose 1959 book Italian Food gave them the courage to introduce hitherto unheard of Italian dishes, such as Piedmontese peppers, in the early Sixties.
David herself visited the Taruschios in 1973, the beginning of a long and respectful friendship. 'Should we say this?' Ann asks Franco. 'Oh, why not. Elizabeth used to say she liked us because there was no bullshit. She would say to Franco, 'Promise me you'll never become a bullshitter,' wagging her finger at him.'
David helped the Taruschios to compose one of their most delicious dishes, Llanover salt duck with pickled gooseberries and damsons. The method to cure the duck was found in Lady Llanover's 1867 cookery book, The First Principles of Good Cookery. Duck breasts are salt- cured for three days, then slowly oven cooked in water - almost coddled - until the meat is tender and silken. The taste is unique, rich, but utterly clean. The pickles cut the richness.
There is no waste in the Taruschios' kitchen. 'I take the kitchen staff out to see how the food is gathered,' says Franco. 'Once they see how much work goes into collecting just a little food, they respect it.'
Last May, he invited me on one such venture: a visit to the cockle beds of Penclawdd, near Carmarthen Bay.
Franco packed a vast picnic and Ann's parents, whom everyone politely addressed as Dr and Mrs Forester, came along. It was bucketing rain. Even so, the kitchen staff rolled up eager, bright-eyed and waterproofed at 9am - and it was their day off.
We were greeted at Penclawdd by one of the oldest cockling families in Wales, the Swistuns. Violet Swistun told Ann about how, when she was a girl, she cowered in the dunes as German planes strafed the cockle beds. Her sons piled us into the wagon of a tractor and transported us, pitching and lurching in driving wind and rain, across Llanrhidian Sands.
Progess was slow and painful. Marsh sheep and horses, recently abandoned by the cocklers in favour of tractors, grazed about us. We were splattered with silt and, stepping out on to the cockle beds, we sank into it.
We were shown how to rake, sieve and rinse cockles in the tide. It was backbreaking. Only on our return did Ann tell us that the beds still contain unexploded shells - from an old munitions works - that wash up regularly. None of us is ever likely to waste a cockle.
That same trip, Franco urged the cocklers to harvest samphire, also known as glasswort, abundant on the marshes. Curious, the local men studied the Italian chef stooping to trim small emerald sprouts and carefully sparing small plants. They will doubtless come round to the idea of collecting samphire.
Long ago, Franco successfully encouraged the locals to hunt for mushrooms. When I arrived last weekend, he had just returned from an expedition, again in rain, that produced a five-kilo haul of porcini. And next morning, a local hunter brought four more kilos.
What is not eaten fresh is frozen, and the abundance is such, says Ann, that 'Jill down the road, her husband is the undertaker, says we can use his spare deep freeze'. And then she laughs.
However, a notable accomplishment of the Taruschios has been to wean the British public from over- reliance on their beloved freezers. Over the years, they have nurtured fishermen who now supply the Walnut Tree with day-fresh fish; farmers who grow rocket, cardoons, chicories and artichokes for the restaurant; and even a neighbour who provides it with suckling pigs. In their own kitchen garden, which tumbles down the hillside from the pub, they grow courgettes, lambs' lettuce, herbs and flowers for the restaurant.
Many of the dishes I have described are in the Taruschios' delightful book. Leaves from the Walnut Tree is a rare cookbook, born not of ambition but of long-acquired knowledge and nurturing of the local community.
If this love letter has a purpose, it is to encourage young chefs to absorb not just the Walnut Tree's recipes, but also the philosophy that lies behind them.
Walnut Tree Inn, Llanddewi Skirrid, near Abergavenny, Gwent (0873 852797). Children's portions on request. Wheelchair access (also wc). Approx pounds 20- pounds 30. Open Tues-Sat lunch and dinner. No credit cards.