The reasons for visiting restaurants are painfully few. One is exhausted, or travelling; there is nothing in the house; everyone else is out to lunch - so why not? But there are also two good reasons for visiting certain kinds of restaurants: if one is a cook, to get a fresh idea; and if one is an eater, to try out the produce or specialities of a region.

Last week, on an abortive attempt to visit the antiques fair at Barjac - abortive because we drove with great care to the wrong Barjac and thus saved vast sums of money - we made a planned overnight stop at one of those small hotels with good restaurants that make touring in France a pleasure. This one was in La Malene in the rugged, campsited Gorges du Tarn in the Lozere. Pretty country, pretty hotel: the Manoir de Montesquiou, a sort of 15th-century fortified castle clinging to the steep sides of a gorge, in the heart of a village of tiny stone houses.

This is not rich agricultural territory. The gorge is one of many fissures in the causse, that huge limestone plateau which tilts up from the back country of the Languedoc into the Massif Central. It is a bare place in which, apart from villages clustered against the wind in the sudden valleys, you might not see a single house for 20 kilometres. It is high pasture, and its main products for the table are lamb (and sheep cheeses) and hams.

In such places one does not know what one is going to get out of a hotel's restaurant. In my experience, it is generally pretty good fare and, occasionally, exceptional. In this case we were extremely lucky for our meal, liberally washed down with one of my favourite local wines, a faugeres called La Liquiere, was excellent. By excellent I do not just mean that we ate well, but that we came out bristling with ideas, new to us, at least.

For instance, combining sweet and salt is a very old principle, one certainly exploited by true Italians, whether in the form of prosciutto with melon or figs or, in my mother's favourite dessert, a simple, perfect pear with chunks of parmesan. It was perhaps in her honour, and because I have inherited her tastes, that I chose for a first course what was described as a pear with poitrine fumee and bleu des Causses: a simple description for a dish of complex flavours.

Bleu des Causses is what one might call a 'lesser' roquefort. Since it is made exclusively with cow's milk it has a creamier, smoother texture and milder flavour, thus having a greater flexibility for use in sauces.

Part of the fun of eating a course such as the pear dish is imagining oneself making it. These were the elements: an immaculate pear, peeled, cored and blanched and placed on a crouton; the smoked pig breast in thin strips, intended to flavour the pear (prosciutto-like, but more subtle); and a superb creamy sauce for the cheese. Thus: two contrasting salts and one sweet. Not difficult to prepare, I imagine, the trick being to make a sauce in which cream and cheese blend perfectly.

I followed this by observing another rule of mine about restaurants: simply, wherever possible, not to eat that which I eat at home. So I chose a joue de porc en daube, or stewed pork cheeks which, like other unmentionable parts of the pig, my wife will buy for my lunches, but would not dream of cooking. The cheeks are meaty, not fat, without sinews and coarse-grained, all properties one looks for in stews, where the meat must be able to resist long, slow cooking. In this case, the discovery lay in the stewing properties of olives which, when cooked at length with a dark and strong wine, lose their acidity and impart a subtle, rich taste.

My wife started with a terrine de lapereau (baby rabbit) which a purist might have said was a bit dry; the same could not be said of her rich chausson (filo pastry turnover) of local trout and Mediterranean scallops, a neat combination of two highly contrasting fish tastes.

We polished off the meal with a tray of local cheeses, from which I chose four contrasting fromages de brebis, or ewe's-milk cheeses. My only mistake lay in ordering a parfait de marrons (chestnuts) which I could not possibly finish.

My point is, I think, made. A visit to a restaurant should be a source of ideas. Which fruit can be used with what cheeses? Are there other dishes which olives will not overwhelm? What additional flavourings were in that cheese sauce and what else might a good creamy bleu be used with? Could other dishes be enhanced by a touch of salt pork? Only moving about and tasting makes one ask such questions.