1 - step 1 Put the milk, cream, cinnamon stick and all the citrus zest in a saucepan set over a medium heat.

2 - Cook, stirring often, until the milk is just steaming but not boiling, about 3-5 mins.

3 - Remove from the heat, cover with a plate and leave to infuse for at least 30 mins.

4 - step 2 When the cream mixture has infused, whisk the egg yolks, sugar and cornflour together in a separate bowl for 3-5 mins, or until light and pale in colour.

5 - Pour the infused milk through a sieve into the egg mixture, whisking continuously.