200g best bitter dark chocolate (Green and Black's Organic Dark Chocolate is good)
2 tbsp brandy
3 large free-range egg whites
50g golden caster sugar
100ml whipping cream
Grate 50g of the chocolate and reserve. Break the rest into small, even-sized pieces and melt in a bowl placed over a pan of simmering water. Take the pan off the heat but keep the bowl over the hot water and stir in the brandy. Don't worry if the mixture thickens - it will smooth out again later.
Whisk the egg whites in a large bowl until they're standing in stiff peaks. Spoon in half the sugar, whisk again, then add the rest of the sugar and whisk until it looks glossy like meringue.
Whip the cream in a separate bowl. Take the melted chocolate off the pan and fold in a heaped metal serving spoon of meringue to loosen the consistency, then tip the chocolate into the meringue and fold in lightly but thoroughly.
Now fold in the whipped cream, then two thirds of the grated chocolate.
Spoon the chocolate mixture into six demitasse cups and chill in the fridge for at least 2 hours, or overnight if this is more convenient.
Sprinkle with the remaining grated chocolate, then dust with icing sugar. Serve the cups on saucers with some crisp biscuits tucked alongside.