Step 1

Put the cream and milk into a large pan and gently bring to just below boiling point. Meanwhile, in a large bowl, whisk the yolks, cornflour, sugar and vanilla. Gradually pour the hot milk mixture onto the sugar mixture, whisking constantly.

Step 2

Wipe out the saucepan and pour the mixture back into it. Heat gently, stirring with a wooden spoon (see Steps 1 and 2, for stirring tips) until the custard is thickened, but before any lumps form. Eat hot or cold.