Place the milk and vanilla extract in a small saucepan over medium heat until steaming lightly, don't boil.
While the milk is heating whisk the egg yolks, cornflour and sugar in a large separate bowl until pale and well combined.
Slowly pour the milk mixture into the egg yolks, if you do this too quickly it will curdle, so very small amounts at a time, whisking continuously.
Pour the milk and egg mixture back in to the saucepan and cook, stiring continuously, over a low to medium heat, until the custard has thickened and coats the
back of a spoon.
Serve immediately over fruits or on its own, or store in the fridge for up to 2 days.
