Whisk egg yolks and sugar in a medium bowl until pale, then whisk in matcha powder until well combined. Set aside.
Heat the milk and cream in a large saucepan until simmering, then remove from heat.
Slowly pour a cup of the milk into the yolks while whisking as quickly as possible. Stir the yolks back into the saucepan of milk.
Continue heating the custard base on medium heat for around five minutes. Once it thickens and coats the back of a spoon, remove from the heat and allow to cool.
Strain the ice cream base into an airtight container and refrigerate for at least 3 hours,preferably overnight.
Churn in an ice cream machine following the manufacturer's instructions, then add to a freezer-proof container and freeze for two hours or until hardened.