Place the cornflour and the 2 tablespoons of milk in a medium size bowl and blend together. Whisk in the sugar with the egg yolks.

Heat the milk, with the vanilla extract, in the sauce pan to boiling point then remove from the heat.

Whisk 5-6 tablespoons of the hot milk into the egg yolk mixture. Pour the remaining hot milk in to the egg mixture in a steady slow stream, whisking continuously.

Pour the contents of the bowl back into the sauce pan. Place the pan over a gentle heat and whisk continuously until thickened. This will take around 4-5 minutes. The sauce will continue to thicken a little as it cools.

Cook's Notes

For a creamier version substitute half the milk for single cream.

For a thicker sauce increase the cornflour from 1 tablespoon to 1½ tablespoons.

Choose a good quality vanilla extract such as Madagascan Bourbon vanilla as this will impart the best flavour.

To prevent a skin forming on the custard whilst cooling, sprinkle a little extra sugar over the surface, or cover the surface with cling film.