Blitz pistachios and 1/2 cup sugar in processor until very finely ground.
Add cream, milk and pistachio mixture to a large saucepan and heat until simmering.
Whisk egg yolks, salt and leftover sugar in a bowl.
Slowly add 1 cup of hot milk mixture to the yolks, all the while whisking as fast as possible.
Pour the custard back into the saucepan and continue cooking over low heat until it thickens and coats the back of a spoon. This usually takes a few minutes and it's important you don't let it boil as you'll cook the eggs.
Strain custard base to remove any pistachio bits.
Add custard to an airtight container and chill for about two hours.
Churn in ice cream maker as per manufacturer's instructions.
Transfer to container and freeze for another two hours until hardened.
