• When you separate the eggs keep one white and throw the other two away.
• Put all three yolks in a bowl with the sugar and whisk it till your forearms bleed (or just enough to make it nice and frothy).
• Add the flour in thirds, each time whisking it through. If you want the final product good and thick add it all, if you prefer it more custard-like, only add the first two thirds.
• Keep whisking.
• Add the extra egg white and whisk some more.
• In a pot, bring the milk and vanilla to the boil.
• SLOWLY pour the milk into the egg mixture, stirring with a spoon or spatula.
• Once it's all mixed in put the whole lot back on a medium heat and stir till it thickens. It takes a few minutes and then happens all of a sudden.
• Leave to cool and then chill.

Tip:

Once you've poured the crème into a bowl, grease some baking paper with butter and place it on top of the mix. This will stop it getting a skin on top.