Every ice-cream cook has to have a chocolate recipe. This is mine. It was after making this and a seed-speckled vanilla that I turned my back on bought ice cream for good. Why stand in a queue at the supermarket when you can be at home making this? By the way, don’t even think about skimping on the quality of the chocolate or the cocoa (there’s plenty of choice nowadays, including Green & Blacks, The Chocolate Society, Valrhona or Lindt Excellence).
This is the same basic method as for my Bay Leaf ice cream recipe, so I've lifted bits straight from that post and inserted them below (the original magazine article simply referred readers back to previous recipes).
100g dark chocolate, 70% cocoa solids
500ml whipping cream (or half and half double cream and full-fat milk)
4 large egg yolks
100g caster sugar (or light brown soft sugar if you prefer)
Break the chocolate into pieces and put in a basin over a pan of shallow simmering water to melt (don’t let the water touch the basin).
Meanwhile whisk eggs and sugar, ideally using an electric hand mixer, until the mixture is pale. Still beating, add the heated cream, then whisk/beat in the chocolate, followed by the cocoa.
Pour the mixture back into the saucepan and heat gently (it must not boil), stirring all the time until the custard has thickened just enough to coat the back of a spoon: a line drawn through it should keep its shape. I allow 10 minutes for this stage.
If you want to take a more cautious approach, instead of heating the mixture in the saucepan, suspend the basin over a pan of shallow simmering water. It will take longer, but you’re as good as guaranteed to produce a smooth custard, not scrambled egg. Decant the custard into a jug and sit it in cold, preferably iced, water. Leave until completely cold.
If using an ice cream maker, follow the manufacturer’s instructions. Without a machine, put the mixture in a suitable container in the coldest part of the freezer. After 90 minutes, take it out and quickly beat to a slush, preferably using an electric hand mixer or a food processor. Repeat the 90-minutes-and-beat process twice more.