1. Coarsely grind the 2 1/2 cups of pistachios in a food processor. Remove and reserve 3/4 cup. Finely grind the remaining pistachios and set them aside, too. Whatever you do, keep your hands out of these they're precisely measured. That's why I suggested the extra cup for snitching.
2. Bring the milk, cream, and the finely ground nuts almost but not quite to a boil in a medium saucepan over medium-high heat. Watch this closely, as it can foam up and over the pot in the time it takes you to grab a potholder. Remove the pan from the heat and stir in the vanilla and salt. Pour the pistachio milk mixture into a bowl and place this bowl in another larger bowl filled halfway with ice and water. Stir the pistachio milk mixture until cool. Cover the bowl with plastic wrap and refrigerate overnight. (The lackadaisical among us can simply slide the pan off the heat and let it cool. Then cover the pan with plastic wrap and place it in the fridge.)
3. The next day, strain the pistachio milk mixture into another saucepan, pressing hard on the ground nuts with the back of a spoon. Discard the soggy nuts. You'll have about 2 cups of wickedly pistachio-flavored creamy milk. Resist the urge to sip it. Heat the milk over low heat until very warm. Again, don't let it boil.
4. Meanwhile, in the bowl of a stand mixer (or using a bowl and one of those handy dandy hand mixers like my godmother used to use), beat the egg yolks and sugar with the whisk attachment until thick and pale, 3 or 4 minutes.
5. Carry the bowl over to the stove and pour just a little of the warm pistachio milk mixture into the whipped egg yolk mixture and stir to combine. Slowly, slowly add the rest of the whipped egg yolk mixture to the pan, stirring constantly with a wooden spoon, until the mixture registers 175 degrees to 180 degrees F (80 degrees to 82 degrees C) on an instant-read thermometer or until the custard that forms thickly coats the back of your spoon and doesn't drip when you swipe your finger across it.
6. Pour the custard into a bowl and place this bowl in another large bowl filled halfway with ice and water. Lazily stir until the mixture cools. Cover the bowl with plastic wrap, gently pressing the plastic directly against the surface of the custard, and refrigerate until completely chilled, about 2 hours. (I know you're asking, What the hell, David? Why all this chilling in a bowl with ice? Good question, astute reader. If you put the hot custard in the fridge immediately, you'll drop the inside temperature of your refrigerator and you could very well spoil your dinner. Also, by making sure the custard is chilled through and through, you'll take some strain off of your ice cream maker especially those of you whose ice cream makers have the inserts you have to freeze. It takes way longer to churn ice cream if the base is warm and the results are never as spectacular as they ought to have been. Trust me that's all I'm going to say.)
7. Churn the gelato according to the manufacturer's instructions. Sprinkle the reserved coarsely ground pistachios during the last few minutes of processing, when the gelato starts making those mesmerizing waves as it goes round and round and round. (Those waves are how I know that the gelato ready.) Scoop the gelato into a plastic container, cover, and freeze until solid. I bought these cool pint-size ice cream containers, just like the ones they use in ice cream parlors. I like to personalize them with my guests names and carry them aloft on a tray to the table. They get a kick out of it and, to be honest, I do, too.
Recipe used with permission. Pistachio Gelato Recipe © 2003 David Leite. Photo © 2003 William Addison. All rights reserved.