Place the vanilla pod, milk and cream in a pan and bring to the boil.
Separate the egg yolks from the whites.
Whisk together the sugar and the egg yolks.
Pour the hot liquid over the egg yolks, stirring all the time. Return to the pan and continue to stir over a medium heat until the sauce thickens and coats the back of a spoon.
«Using a clean pan for the cooking of the custard will reduce the risk of it catching on the bottom and burning.»