250ml/8fl oz double cream
250ml/8fl oz whole milk
1 vanilla bean, split in half lengthwise
5 egg yolks
125ml/4oz caster sugar
4tbsp chestnut honey
Heat the oven to 150C/300F/Gas2.
Start by making the ice cream base. Combine the cream and the milk in a heavy-based saucepan. Add the vanilla pod. (I tend not to scrape out the seeds unless I am specifically making vanilla ice cream.)
Place over a medium heat and bring to just under the boil. Remove and cover with a lid and leave to infuse for 5 minutes or so. In a large bowl, meanwhile, whisk the egg yolk and the sugar until thick and pale. Pour in the hot liquid and stir to combine, return the mixture to the pan. Turn the heat down to low and return the pan to the stove.
Using a wooden spoon, stir the custard slowly and consistently until it begins to thicken. (I use a figure-of-eight movement.) The time this takes varies, but ideally you should know when the custard is thick enough when it starts to coat the wooden spoon. You can test this by running your index finger along the back of the spoon; if a ribbon trail is left, your custard is ready. Quickly remove from the heat, pour into a bowl and allow to cool. (Homemade ice cream does not keep well; it is at its best for only a couple of days.)
Next, place the hazelnuts on a baking tray and roast slowly in the hot oven for 20 minutes. Remove from the oven and allow to cool. Pulse in a Magimix (or use a pestle and mortar) until the nuts are coarsely ground.
Place the cooled custard in an ice-cream maker and allow to half set. Add the ground hazelnuts and continue until the ice cream has properly set. Scoop into bowls and drizzle the chestnut honey over the top. Serve immediately.