One of the few good reasons I know for eating out, beyond necessity, is that occasionally one will learn new things or be forced to think through some of one's prejudices. Last week I visited a steamy, pre-World Cup Washington DC. My childhood memories of the place are of native Southern somnolence, gastronomical and otherwise, contrasted with diplomatic opulence - dinner among the latter being something like a cattle fair, with ribbons for the most important guests or the most tendentious arguments.

This time, rather than staying at one of the traditional fancy (and enormous) hotels, at the recommendation of a friend I stayed at the Jefferson. It comes as close as I can think of to being exactly what a first-class hotel should be: small enough (100 rooms) to know all its customers, intelligent enough to hire and train a polite staff, and with a restaurant good enough to make me eat there three times and go out but once - when my ordinary rule is to eat in the hotel only on the first night, and never again.

Will Greenwood, a native Oklahoman, has been the Jefferson's executive chef since 1989. He has developed a sprightly cuisine, lightly based on Southern nostalgia: that is, on the use of certain flavours and textures associated with the dishes and smells of childhood. As a Southern childhood has much to commend it, the result, thoroughly modernised and with the most varied (and fresh) ingredients, was a constant pleasure. My own sense of this tradition was my initiation into American cooking on the distinctively Southern, solidly

negro-chefed, Southern Pacific's restaurant cars, complete with grits, cornbread, beans and a prevailing back-taste of bacon.

As good writers have new ways with language, so good chefs work inventively with their own lexicon, trying new combinations, changing old ones in subtle ways. Take my choice on the first night: hickory-smoked duck with a blueberry, sage and rhubarb sauce. I yield to no man in my liking of the flavours in this dish: I love smoked meats; I think duck is far tastier than chicken; I adore rhubarb; and my wife accuses me of overdoing the sage (a primordial flavour in Southern poultry cooking.)

Greenwood has some interesting ideas in this dish. First and foremost, that of smoking the duck, which he does in-house and with hickory, which adds to the bird a new world overtone of the barbecue. But to offset the smoke (or, if you will, civilise the barbecue), he adds a sauce that I would have thought highly unlikely, nay improbable: the base slightly caramelised, the fruit added, reduced and given a veal glaze.

This I think of as jockeying with flavours, pitting one set (meat and smoke) against another (fruit and sweetness). Accompanied by a Drouhin Pinot Noir from Oregon (thank God for the Northwest, Oregon and Washington state to save us from the enslavement of most of those lustre-less California sauvignons), this was utterly delectable. Number Five Son, who is now past six and begins to know what he does not like (oysters and kidneys), lapped his up.

Greenwood's menu is strictly seasonal in its main dishes, but in all its chief aspects it does that rather rare thing of combining innovation with classical restraint. There are no end of restaurants that can put together unlikely combinations of tastes; few have the skill to see to it that they are properly prepared, blended in just the right proportions and finished accordingly.

Among the appetisers, I chose a warm terrine of barbecued beef ribs with watercress. Who but a cook with flair would ever think of making a terrine out of such a crude (and delicious) meat as a barbecued rib? Has it occurred to you to make a crab-and-lobster cake and combine it with a highly spiced (Pommery) mustard? Or reproduce one of the oldest food combinations, oysters and meat, by spicing up pan-fried oysters and serving them on braised greens and bacon?

Even more admirable is that the restaurant functions just as well when a chef produces his daily specials. I called Greenwood to get the recipe for swordfish salad, of which the chief component was a massive amount of fresh mint, but he did not know the dish. It had been his chef's invention. Well, no sooner back, I served it at home, altered; and a better summer dish I could not offer you. I used chicken, generously coated with Jamaican jerk spices, sauteed in the residue of cooking some coarse-diced pancetta.

First I made my traditional salad dressing: olive oil, red wine vinegar, thinly sliced spring onions, 1tsp of dry English mustard, two fresh cloves (ground), 1tsp of sugar and 1tbs of fruit glaze (in this case passion-fruit, but any fruity sauce will do), plus some fresh thyme from the garden. To this I added red lettuce; at the last moment, still very hot, the pancetta and chicken; and then, before mixing, a generous handful of fresh mint leaves.

That is what I mean by learning by eating out (advice Greenwood himself was given when young). It gives you ideas.