By Jeremy Round
Preferably using a non-stick saucepan, heat the milk with the sugar and vanilla pod. Bring mixture very slowly to the boil.
Beat yolks in a bowl with a wooden spoon, without allowing them to become too frothy.
Remove vanilla pod (which can be wiped and reused many times) from the milk. Pour milk on to the yolks in a steady stream, stirring all the time. Return to the pan when we