For the pistachio flour:
2 cups shelled raw pistachios
1 cup slivered, blanched almonds
1/2 cup confectioner's sugar
For the gelato:
4 cups whole milk
1/2 cup sugar
3 1/2 tablespoons cornstarch
1/4 teaspoon almond extract
1/4 teaspoon sea salt
1/4 teaspoon lemon juice
DIRECTIONS
1. First make the pistachio flour: In the bowl of the food processor, combine the pistachios, almonds and confectioner's sugar. Pulse until you get a fine, mealy texture, adding more sugar if necessary to keep the nuts from sticking together.
2. Next make the gelato base: In a bowl, whisk together 1/4 cup of the milk with the cornstarch to make a slurry. Heat the remainder of the milk in a saucepan with the sugar. Just before the milk boils, stir in the cornstarch slurry and simmer for 3 to 5 minutes, stirring constantly as it thickens. Remove from the heat and stir in the pistachio and almond flour mixture, almond extract and salt. Chill thoroughly, preferably overnight.
3. Once the base is chilled, whisk in the lemon juice until smooth. Freeze the gelato in your ice cream machine according to the manufacturer's instructions.
