What to buy: Sahlab is a starch made from a powdered root. Both it and mastic are available in specialty food stores. The sahlab available in the US is mixed with cornstarch, that’s why 4 tablespoons are necessary.
1Dissolve the sahlab in 1 cup cold milk. Mix very well until the mixture is quite smooth.
2In a large saucepan, stir the rest of the milk and sugar together and bring to a boil over medium heat.
3Add the sahlab mixture and mastic to the warm milk in the saucepan. Simmer over medium heat, stirring constantly, until the mixture thickens. At this stage, the mixture should be slightly elastic. Remove the pan from the heat.
4Add saffron-rose water. Mix well. Allow to cool for 2 hours. Pour the entire mixture into an ice-cream machine.
5Follow your ice-cream machine’s directions for making ice cream (my machine takes about 1 hour and 40 minutes).
6Pour a thin layer of whipping cream into a flat plate and place it in the freezer until a 1/4-inch frozen creamy crust forms. Remove the crust from the freezer, let it stand for 2 minutes, then break off 1/2-inch pieces of the crust and mix them with the finished ice cream. Transfer to a press-in-lid plastic container, cover, and keep in the freezer to allow the taste to develop.
7Serve saffron ice cream in small crystal bowls; sprinkle the top with ground pistachios. Nush-e Jan!
Variation: You may simply use 1 pint vanilla ice cream. Add frozen cream pieces, saffron-rose water, and slivered pistachios. Mix well.