Put the milk into a saucepan with two-thirds of the sugar, add the vanilla pod and bring it to the boil over a medium heat.
Cook over a low heat, stirring with a wooden spatula or spoon, until the custard lightly coats the back of the spatula. When you run your finger through, it should leave a clear trace immediately take the pan off the heat.
Meanwhile, whisk the egg yolks and remaining sugar together in a bowl to a light ribbon consistency.
Pour the boiling milk on to the egg yolks, whisking continuously, then pour the mixture back into the saucepan.
Unless you are serving the crème anglaise warm, pour into a bowl and leave to cool stirring occasionally to prevent a skin forming. When cold, pass through a chinos.