Preheat oven to 320°F (160°C). Spread the pistachios on a baking sheet and toast for 8-10 minutes, just until fragrant. Watch closely so they don't brown or burn.
Let the pistachios cool slightly, then add them to a food processor or coffee grinder with half the sugar (50g / ¼ cup). Pulse until very finely ground, almost powder like.
In a saucepan, combine the milk, heavy cream, and ground pistachio-sugar mixture. Warm over medium heat, stirring occasionally, until steaming and just below a simmer. Do not let it boil.
Meanwhile, in a separate bowl, whisk the egg yolks with the remaining sugar (50g / ¼ cup) until well combined.
Slowly ladle the warm pistachio milk into the egg yolks, whisking constantly, to temper the eggs. Add it gradually until incorporated.
Pour the tempered egg mixture back into the saucepan. Cook over medium-low heat, stirring constantly, until the custard thickens enough to coat the back of a spoon. Do not let it boil.
Remove from heat and stir in the salt and vanilla. If the pistachio bits seem unevenly distributed, blend briefly with an immersion blender.
Let the base cool to room temperature, then cover and refrigerate for at least 4 hours, or ideally overnight, until completely cold.
Pour the chilled base into a pre-frozen ice cream maker bowl and churn according to the manufacturer's instructions until thick and soft-serve in texture.
Transfer to an airtight container and freeze for about 2 hours for a scoopable texture, or serve immediately for a softer consistency.
