Cocoa's Chanel

I once knew a Belgravia resident who had served three years inside for his part in a gem fraud. On his release, he said, it meant a great deal to him that none of the grocery shops in Elizabeth Street had closed his account.

This quixotic tale has always stuck in my memory, and I cannot visit Elizabeth Street without recalling it. Especially now he would also have fine French chocolate to look forward to, given that Elizabeth Street is home to the first French-style chocolate shop to open this side of the Channel.

It should come as no surprise that the man behind the shop is Alan Porter who founded The Chocolate Society in 1990 and is solely responsible for putting the delectable, grand-cru dark couvertures of Valrhona on the map.

Porter started importing Valrhona nine years ago through his company, Porter's, which also supplies such delicacies as foie gras and morels to restaurants. It was love at first bite, he says: "I had never tasted anything like it and have wanted to focus more on the product ever since." Last November, he sold his shares in Porter's, took over a premises in Elizabeth Street and opened The Chocolate Society shop.

Shelves are lined with the society's drinking chocolate, rich chocolate biscuits, sticky sauces and discs flavoured with natural essences such as Kent hops and juniper. All are only made with Valrhona couvertures - the likes of Guanaja, Manjari and Pur Caraibe, all produced from rare cocoa varieties. This includes the hot chocolate: "We take 40 grams of Manjari, steam it a little to soften it, then add milk and steam that into a froth." And that's it - half a bar of chocolate in a glass of hot milk.

To bring out the flavour, you can choose from a grinding of fresh nutmeg, or a particularly pungent pepper from India's Wynad Valley. I was also seduced by their range of Russian teas - called Kusmi, they are packed in exquisitely ornate paper and tied with raffia. I'm not a great one for flavoured teas, but these are delicate - spiked with aromatics such as cinnamon, mandarin and bergamot.

There is the beginning of a range of patisserie that I suspect will prove the undoing of many a Belgravia resident. Currently, it's confined to an upmarket chocolate fridge cake called Belgravia Block and another confection that falls somewhere between fudge and praline. They also sell all the couvertures by weight - in thick, broken slabs - which is ideal for cooking.

But the main point, of course, are the truffles and chocolates. Unlike English chocolates, which are centres within shells, French-style chocolates are centres that have been enrobed within a thin chocolate coating. It's a chocolate-based chocolate, as opposed to a fondant. "We don't approve of fondants in chocolates," says Porter. "We're trying to sell the concept of purity."

If you are used to a box of chocolates with a surprise centre of a different colour and consistency in every one, then you might find French chocolates sober by comparison. Although Porter does want to play on English flavours - "a ganache made with sloe berries or flavoured with rose", for example.

If Belgravia is a long way off for you, they do mail order, and there are plans to open shops in Edinburgh, Glasgow, Bristol, Birmingham, Bath and Manchester. I hope that it happens. Given the depth of Porter's addiction, I imagine it will.

Chocolate almond cake with ganache, makes 1x23cm/9" cake

There's no flour in the cake sponge, or butter, but it's beautifully moist and rich, coated with shiny ganache.

Having devised this for a couverture chocolate I can't vouch for how it will turn out with an ordinary plain chocolate. Dark couvertures have less sugar, more cocoa and more cocoa butter than ordinary chocolate so they will behave differently in recipes.

Sponge:

250g/9oz dark couverture chocolate

6 large eggs, separated

150g/5oz caster sugar

3 tbsp Cointreau

225g/8oz ground almonds

I level tsp baking powder, sifted

Ganache:

150g/5oz dark couverture chocolate

5 tbsp single cream

50g/2oz unsalted butter

40g/112oz toasted and chopped hazlenuts

To make the sponge, heat the oven to 170C (fan oven)/180(electric oven)/350F/Gas 4 and butter a 23 cm/9" cake tin with a removable base. Cut up the chocolate and place in the top half of a double boiler (or in a bowl over simmering water) and gently melt. Periodically, remove it from the heat.

Whisk the egg yolks and sugar in a bowl until pale, then whisk in the melted chocolate and the Cointreau. Whisk the egg whites in a clean bowl until stiff and gradually fold them into the chocolate-egg yolk mixture. Work through the ground almonds with your fingers to make sure any lumps are broken up, then fold these and the baking powder into the chocolate mixture and pour it into the prepared tin.

Bake for 35-40 minutes until it is risen and firm and a skewer comes out clean from the centre. Remove the collar and cool.

Cut up the chocolate for the ganache and place in the top half of a double boiler or bowl over simmering water, with the cream and butter and melt. Place the mixture in a liquidiser and whizz until it is glossy. Smooth it over the top of the cake, and a little over the sides using a palette knife. Then press the hazlenuts around the sides, using a teaspoon to help. Leave to set in a cool place for several hours, but not the fridge. It is nicest left overnight, so the texture of the cake can develop

The Chocolate Society, 36 Elizabeth Street, London SWI (0171-259-9222)