1 1/2 tbsp shelled and peeled pistachios (raw or roasted salted)
1/2 tsp ground cardamom
1 whole cinnamon stick
1 pinch saffron threads
1/4 tsp freshly grated nutmeg
2 cup whole milk
3 1/2 tbsp light brown sugar
1/8 tsp salt
2 cup water
5 tsp loose black tea leaves
4 oz gin
Finely grind nuts, cardamom, cinnamon, and saffron with mortar and pestle or in grinder.
Bring milk just to a simmer in a 2-quart heavy saucepan, then whisk in brown sugar, salt, and nut mixture and cook over low heat, stirring occasionally, 3 minutes to infuse flavors.
Meanwhile, bring water to a boil in a 1-quart saucepan, then add tea leaves and boil 1 minute.
Pour tea through a fine-mesh sieve into hot-milk mixture, discarding tea leaves, and cook chai over low heat 1 minute.
Divide gin among 4 (8-ounce) mugs and top with hot chai.