Blanch pistachios in boiling water for one minute, then transfer to an ice bath

Gently rub pistachios to remove skins, then pat dry completely

Process skinned pistachios in a food processor until they form a fine paste or crumbs

Pour milk and cream into a medium saucepan and heat over moderate heat until steam appears

Whisk egg yolks and sugar in a separate bowl until pale and thick

Slowly pour the warm milk mixture into the egg mixture while whisking constantly

Return the mixture to the saucepan and cook while stirring, until it coats the back of a spoon

Remove from heat and stir in ground pistachios, vanilla extract, and salt

Allow the mixture to cool to room temperature

Cover and refrigerate for at least four hours or overnight

Strain through a fine-mesh sieve if desired for a smoother texture

Pour chilled custard into an ice cream maker and churn for 20 to 25 minutes

Transfer to a freezer-safe container and freeze until firm, about four hours