From: Mixologist Holly Zack, The Wallace, Culver City, CA.

2 oz. London Dry Gin
¾ oz. Earl Grey syrup
½ lemon

Foam:
3 oz. pistachio liqueur
1 oz. Earl Grey syrup
4 oz. egg white
6 oz. water
½ Tbsp. citric acid

Shake drink ingredients hard and strain. Top with pistachio foam.

For pistachio foam: Mix ingredients and charge in iSi.