Bring 400 ml of milk to the boil with 40 g of sugar. Cut open the vanilla pod and squeeze out the pulp.
Mix the cornstarch with the vanilla pulp and add to the remaining cold milk.
Add the liquid cornstarch to the hot milk and cook for 2 minutes, stirring constantly.
Remove the saucepan from the heat. Beat the egg yolks with the remaining sugar until creamy and add to the hot mixture.
Transfer to a large enough bowl and leave to cool.
Arrange and serve the pudding as you like or use it further.