1. In a saucepan, combine the heavy cream, whole milk, and grated ginger. Heat until just simmering.
2. In a separate bowl, whisk the egg yolks and sugar until pale and thick.
3. Slowly pour the hot cream mixture into the egg yolks, whisking constantly.
4. Return the mixture to the saucepan and cook over low heat, stirring constantly, until it thickens and coats the back of a spoon.
5. Strain the mixture through a fine-mesh sieve into a bowl. Let it cool to room temperature, then chill in the refrigerator for at least 4 hours.
6. Pour the chilled mixture into an ice cream maker and churn according to the manufacturer's instructions.
7. Transfer the ice cream to a container and freeze until firm, about 2 hours.