Step 1

Muddle sage leaves, sugar, and 4 cucumber slices in a cocktail shaker. Add egg white, gin, lemon juice, simple syrup, St-Germain, and a dash of bitters. Cover and shake vigorously until egg white is very frothy, about 1 minute.

Step 2

Fill shaker with ice and shake vigorously until outside is frosty, about 1 minute. Pour into a coupe glass and garnish with remaining cucumber slice.