Preheat the oven to 350 F. Spread shelled pistachios on a baking pan in an even layer.

For raw pistachios, toast them for 9-10 minutes, until very hot and fragrant. For roasted pistachios, toast them for 5-7 minutes, also until fragrant and hot. For both, shake the pan halfway through the toasting time.

Pour the nuts into a strong blender or a food processor - careful they will be hot so use a spoon or an oven mitt. Begin processing them on high, the nuts will first turn finely chopped then powdery, then it will start to turn into a thick paste. Keep processing until you have a very smooth, runny paste. Transfer to a heat proof jar and chill.

In a large pot, add the milk, cream, sugar, eggs and salt. Whisk well to break up the eggs.

Set the pot over medium low heat. Cook until the custard thickens and registers 160 F on a thermometer. Pour the mixture into a heat proof bowl through a fine mesh sieve (this will remove any egg bits that cooked before being mixed into the custard).

Add in 180g or ⅔ cup of pistachio paste and the vanilla and whisk well to combine. Let cool to room temperature then cover with plastic wrap to seal and set in the fridge to chill overnight.

The next day, there will probably be a thickened layer of custard on top - mix it in then pour the base into the bowl of your ice cream machine. Churn according to machine instructions.

Store the ice cream in a freezer safe container. It’ll keep for about 2 weeks.