Prepare all the ingredients.

In a saucepan, bring the milk to a boil.

Add the crème fraîche.

Separate yolks from whites

Add the caster sugar.

... and whisk the mixture until white in colour.

Add the boiling milk and crème while stirring.

Cook very slowly on a hob or on very low heat. The use of an induction hob is very useful for this kind of delicate cooking.

Constantly stir using a wooden spatula. The mixture should coat the wooden spoon.

When finished, sieve the mixture using a chinois or a fine sieve.

Leave to cool. Store in a cold place.