2 oz. Gin - (more)
1 Egg White - (more)
1 tsp. Green Creme de Menthe - (more)
1 tsp. Powdered Sugar - (more)
1/2 Lemon (Juice of, fresh) - (more)
Carbonated Water - (more)
Shake all ingredients (except carbonated water) with ice and strain into a highball glass over 2 ice cubes. Fill with carbonated water, stir, and serve.