This easy custard is great for everyday puddings and is also a skill that's useful for other recipes like ice cream.
Heat the milk and the vanilla pod and seeds in a pan over a medium heat, stirring frequently, until just coming up to boiling. Set aside for 15 minutes to infuse and cool slightly.
Mix together the egg yolks, sugar and cornflour in a heatproof bowl stirring to get a smooth paste.
Slowly pour the hot milk into the paste, stirring constantly until completely combined.
Strain the mixture into a clean saucepan and, stirring constantly, cook gently over a low heat until the custard thickens. This happens at around 75C/165F, if you have a cooking thermometer. If you don't, coat the back of the spoon with custard and draw a line through with your finger. If the line holds, the custard is ready.
You can substitute 1 tsp vanilla extract for the vanilla pod. Just add it after the eggs and milk have thickened and before it cools.
You can remove, wash and dry the vanilla pod to re-use in another recipe, such as vanilla sugar.