In a medium saucepan, heat heavy cream and whole milk over medium heat until steaming (about 170°F). Do not boil.

In a separate bowl, whisk egg yolks, granulated sugar, and brown sugar until pale and slightly thickened.

Slowly pour warm cream mixture into egg yolks while whisking constantly to temper.

Return mixture to saucepan. Cook over low heat, stirring continuously, until custard thickens and coats the back of a spoon (175–180°F).

Strain through a fine mesh sieve into a clean bowl.

Whisk in pistachio paste, ground pistachios, chopped mint, peppermint extract, vanilla extract, and salt until fully incorporated.

Cool mixture over an ice bath, then refrigerate at least 4 hours or overnight.

Churn in an ice cream maker according to manufacturer’s instructions until soft-serve consistency.

Add green food coloring during final minute of churning if desired.

Transfer to airtight container and freeze 4 hours until firm and scoopable