In these days of global cooking, thank goodness for a classic French dish you cannot make without visiting France (no matter what Delia says)
One of my most endearing memories of the late Elizabeth David is of her almost pathological belief in accuracy. This highly laudable obsession also branched off into an intolerance of stupidity, insincerity, plagiarism, dishonesty and plain bad taste.

Apart from being a devoted disciple of her evocative recipes and sensitively written prose (I came to ED's books much later in life than most cooksmiths I know), I found myself encouraged by her rage over the slightest inaccuracy. Slapdash factual notes over, say, the origins of a Greek fish paste, the correct method of fashioning an authentic bouillabaisse (including its correct spelling), the chosen herb to use in a sauce paloise (it's mint, for the record) or the proper way to dress a green salad, would have her reaching, exasperated, for her endless supply of little booklets of Post- it notes.

I would dearly love to be having an angry natter with ED just now. In fact, it shocks me to have to admit how cross I was when I learnt of her death - seven years ago now - as there was still so much to talk about, rant over, or giggle wickedly about (usually with reference to a perfectly daft recipe in some magazine or other) whilst quaffing a glass or two of fruity Beaujolais or properly chilled white Burgundy. And if I was to spend much of the twilight months of my life in my bed, as did ED, then I, too, would have a fridge in my bedroom in which to keep the Chablis nice and cool.

I will never forget the first time that I tasted l'aligot (pronounced "lalligo"), in the unremarkable town of Laguiole (pronounced "lie-yol") in the generously unpopulated Auvergne region of southern France. Laguiole is near nowhere in particular and a little time to get there should be afforded, but to those who are familiar with a very particular kind of knife, the designer Philippe Starck and a chef called Michel Bras, the town and its wild hinterland will surely be well known. Before I returned there two years ago, my one and only memory of the place was of these creamed potatoes with cheese: la veritable aligot.

On that first occasion, 12 years ago, Michel Bras had his simple restaurant slap bang in the middle of the town. I remember its interior as being quite brown, really, with the sort of furnishings more at home in a branch of MFI. But you will now find the twice-stellated Monsieur Bras high up on a windy hill a few miles outside the town, all glassed-in and swish, in the best possible taste - well, un peu Franco-moderne, perhaps; the tablecloth edges are now pleated, folded and then stitched underneath the table-tops ... but at least they are not brown. I am also pleased to report that l'aligot still reigns supreme, as Bras remains passionately dedicated to his region.

Now here's the difficult bit. You cannot make l'aligot at home. You see, it must be made using a cheese of the region, a fresh tomme de Cantal. Mature Cantal is not uncommon in France, but this particular local fresh cheese should not be more than three to four days old. I was most emphatically informed of this important culinary fact when I bought a few hundred grams from a fierce madame in the town square. I had the distinct feeling that she would not have let me have some unless I promised to agree to her strict commands. So I jolly well did.

It worked a treat the very next day, once my friend Lindsey Bareham and I had raced (for the cheese's sake, you understand) cross-country to our little Dordogne cottage, in which we were to spend a rainy week working on The Prawn Cocktail Years. Once I had made myself familiar with the kitchen, the potatoes went on to cook, a little garlic was peeled, cream was heated and cheese grated. The immature Cantal was very white - almost like Greek feta in colour and consistency - and smelt sweet and lactic.

Once the dish was assembled, I was thrilled to find that, in exactly the same way it had been presented to us in Laguiole, the consistency of the puree performed its special magic. For when this particular cheese melts and blends into the mashed potato, it becomes as elastic as bubble gum; so much so, in fact, that you just cannot stretch your arm high enough, when lifting some of the mass from the pan, to separate a serving. We laughed to see such fun, as we played with our food.

I find it perversely satisfying, in these days of relentless culinary borrowing, that here is a foreign dish we cannot make at home. We do not have its most important ingredient, nor is it feasible to import it easily before it becomes past its best.

Yet Elizabeth David and, more recently, Delia Smith, both implied that a Lancashire cheese would be suitable for making l'aligot. I strongly disagree. It isn't truly accurate. It is not simply potatoes with some cheese. If you want a souvenir from Laguiole that will perform correctly, visit the Philippe Starck-designed factory and bring back a knife with a bee on it