In a medium saucepan, combine the double cream, whole milk, and the zest of one orange. Warm the mixture over medium heat until steaming but not boiling, then remove it from the heat. Let it rest for 1 hour.

In a large mixing bowl, whisk the ricotta until smooth and creamy. Gradually add the cream mixture to the ricotta while continuously whisking to combine.

Return the saucepan with the ricotta mixture to medium heat. Warm gently until it approaches simmering, stirring occasionally for about 5 minutes.

In a separate bowl, vigorously whisk the egg yolks and caster sugar until smooth and pale, roughly 2-3 minutes.

Carefully pour the warm ricotta mixture into the egg yolks while whisking constantly.

Pour the combined mixture back into the saucepan and stir continuously for about 5-7 minutes until thickened enough to coat the back of a spoon.

Strain the mixture through a fine sieve into a jug to eliminate any zest. Allow it to cool slightly, then refrigerate for at least 4 hours.

When ready, pour the chilled custard into your ice cream maker and churn according to the manufacturer’s instructions, usually around 20 minutes. In the last minute, add the chopped dark chocolate.

Transfer the churned ice cream into an airtight container and freeze for at least 8 hours to firm up completely.