400 ml milk

30 g cornflour

75 g sugar

2 eggs

pinch butter

dripple vanilla extract

Heat milk on hob.

In jug, mix everything else.

When milk is bubbling/rippling/shows any surface movement (not boiling), turn down the heat to medium and pour gradually into jug whilst mixing straight away.

Put back into pan and heat gently, stirring, until starts to thicken.