Proper homemade custard

Method

1. Heat the double cream and milk with the vanilla extract (or paste) and let it simmer gently for a few minutes to infuse. Meanwhile, beat the egg yolks and  caster sugar in a heatproof bowl until pale and thick. Slowly pour the hot cream/milk into the egg mixture and whisk together quickly to combine.
2. Strain the custard into a clean, heavy-based pan and put over a low heat. Stir the custard constantly with a wooden spoon as it thickens – keep the heat gentle and the custard moving or it may curdle. The custard should be ready after about 8 minutes, and be thick enough to coat the back of the wooden spoon.