- Fill a champagne glass with half of the ice cubes (½ cup/75 g) for 5 minutes to chill the glass. Discard the ice cubes.
- In a cocktail shaker, vigorously combine the gin, lemon juice, syrup and the remaining ice cubes (½ cup/75 g). Filter into the chilled glass. Top up with the champagne and garnish with the lemon zest.