The name's unpronounceable, but my goodness the cheese is easy to get your mouth around. One of the highlights of my working life is getting to go to Paris's Salon de Fromages every two years. It's a glorious trade fair of all that is best in the French cheese world. It attracts a huge cross-section of French cheesemakers, from large creameries to independent fermiers, and there's always something new to discover.

Hyelzas is a tiny village of around 50 inhabitants situated just outside Cevennes national park. It's home to a small Fromagerie specialising in making sheep's milk cheeses from the many nearby herds.

This year, they've been experimenting with some new cheeses. Which they've saddled with some of the hardest-to-pronounce-if-you're-a-clodhopping-monolingual-Englishman names I've ever come across. Le Sounal de Hyelzas and Claousou de Hyelzas do anything but trip off your tongue, but saying the name isn't really the point. The point is eating the cheese, and it is extraordinary. 

Both cheeses are made in a similar style to a Vacherin Mont d'Or, so they're soft, unctuous little numbers, bound in birch bark and washed in brine as they mature. The cheese is fabulous: a sweet, nutty flavour with a resinous edge given it by the bark. Unlike Mont d'Or, the bark isn't fastened by metal staples, but by tiny wooden pegs. Both cheeses are beautiful - the Sounal is a large, cutting cheese, while the Claousou is a small, shoe-shaped cheese.

It's not very often in the cheese world that something entirely new happens, and it's even rarer that we're there at the very start, but we've managed it in this case. The first cheeses were made in March, and they first went on sale in early April. And as far as we know, if you want some, you'll have to come to Chiswick, because we're the very first people in the country to have it. And you know, you really should.

The evenings might be darker, the days shorter and the weather colder, but there are some compensations to the onset of winter. I get to wear more flattering clothes again, I can make more casseroles, and I get to spoon melted cheese from a box onto potatoes and pretend it’s dinner.

Yep, Vacherin Mont d’Or is back.

Actually, the name’s a bit misleading. The name Vacherin has been the source of a vicious turf war (or something) between France and Switzerland for decades. Both make a similar cheese, so both claim the right to the name. The outcome of the eventual entente between the two nations was that the Swiss got to call their cheese Vacherin, while the French would call it Mont d’Or.

Pretty unfair, if you ask me, since the French cheese was almost certainly the original, but them’s the breaks.

Anyway, whichever side of the border you get it from, the cheeses are very similar. A soft, oozy interior, covered by an undulating reddish-tinged rind, all held in place with a belt made of spruce bark. They’re stored and matured in a pine box, which, if you’re so inclined, you can put straight into a moderate oven, and bake for about half an hour for a luxurious instant fondue. Spooned over potatoes, cornichons and bacon, it’s a fantastic winter treat – the sort of food it almost makes it worth going skiing for.

It’s also one of the only truly seasonal cheeses. The terms of its AOC stipulate that it can only be made between August and March, using winter milk. The reasons for this are purely historical. This area of the Alps traditionally practices transhumance – farmers will keep their cows indoors in winter, then take them up to the high mountain pastures in summer, where they can graze on fresh grass and mountain herbs for four months of the year. During this time, milk yields go up enormously, which isn’t exactly ideal, since getting fresh milk off a mountain in good time to take it to market is tricky, to say the least. So farmers need to make a big cheese – big enough to use up all that fabulous milk their cows are producing. So they make Comté, one wheel of which is big enough to accommodate a day’s milking for an average size herd.

But in the winter, the cows’ yield goes down, so the farmers need to make a smaller cheese. Since they’re in the valleys, it doesn’t need to be so robust or mature, so they make a soft, reasonably quick to ripen cheese like a Mont d’Or. Exactly like a Mont d’Or, in fact.

So a Mont d’Or is only made in winter, and, since it doesn’t keep for very long, is only eaten in winter. And its arrival and its leaving are as fine a marker point for the changing of the seasons as you could possibly want.