Bring the milk with the cream, the scraped out vanilla pulp and the pod to the boil. Mix the egg yolks with the sugar in a second saucepan, remove the vanilla pod from the milk and pour the hot milk over the egg yolks. Stir with a whisk over medium heat (do not boil) until the mixture becomes thick and creamy. Pour through a fine sieve into a jug and refrigerate.
Keeps in the refrigerator for several days and can therefore be prepared well.