Add the milk and cream to a large heavy-bottom saucepan and gently scald it. While the milk and cream mixture is scalding, add 1/2 cup of pistachios and the granulated sugar to a food processor, blend until a fine paste forms.
Pour the pistachio paste into the cream and milk mixture, then continue to heat it, constantly whisking every minute until the sugar dissolves about 3-4 minutes. Set the ice cream base aside.
Add the egg yolks to a medium mixing bowl and beat well using a whisk. Slowly pour a cup of the hot cream pistachio mixture into the eggs, constantly whisking to prevent the eggs from coagulating. Gradually pour the egg mixture into a steady stream back into the heavy bottom saucepan with the remaining cream, stir to combine, then simmer the base over medium-low heat for 5-10 minutes, stirring every so often until the custard thickens and reaches a temperature of 170 F.
Remove the ice cream base from the range and pour it through a fine-mesh sieve placed on top of a large mixing bowl, then stir in the almond and vanilla extracts. Let the pistachio ice cream base cool to room temperature, then place a plastic wrap over it, directly pressing it into the base to stop skin from forming on the surface of the ice cream base. Refrigerate the base overnight.
Take the pistachio ice cream base out of the refrigerator, pour it into an ice cream machine, and churn according to the producer's directions. Once the ice cream doubles in volume, roughly chop the remaining pistachios and fold them into the base. Place the pistachio ice cream into a freezer-safe container and chill for 3-4 hours before serving.