Provided by: Chefs Geoffrey Zakarian, Sean Rawlinson
Remove the outer leaves of the lemongrass, and slice approximately 20 dime-size circles from the bottom of the stalk. Place the circles into the bottom of a large mojito glass. Mix the lime juice and simple syrup together, add to the lemongrass, and muddle with a thick wooden spoon.
Pour in the gin, Grand Marnier, and Cointreau, and stir. Add ice, top off with soda water, and garnish with the remaining lemongrass stalk.
Boil 1 cup sugar and 1 cup water in a saucepan a few seconds till dissolved; let cool.