1. Mix milk and heavy cream in a pan and bring to a simmer.
2. Meanwhile, mix egg yolk, sugar, cornflour and vanilla extract in a bowl and whisk until combined.
3. Slowly pour milk and heavy cream into the mixture in the bowl while whisking (so the eggs don’t scramble
and you have a smooth custard).
4. Return mixture into the pan and stir over heat until you end up with a thicker liquid (usually when the custard
reaches a boil).
5. Enjoy!