1 To make the custard; whisk the yolks, sugar and scraped vanilla seeds in a bowl.
2 Pour the milk into a saucepan and bring to a boil thenpour on to the egg mixture. Return to the cleaned saucepan and stir over a gentle heat with a wooden spoon.
3 When the mixture is thick enough to coat the back of the spoon, remove from the heat and cool. Make sure it does not boil or the custard will split.