Rosemary Simple syrup:
In a small saucepan over medium heat, combine sugar, water, and rosemary. When mixture boils, reduce heat to low heat, simmer and steep for 15 minutes. Remove rosemary sprig, and strain into a glass container or jar with a lid. Chill until ready to use.
Cocktail:
Combine gin, simple syrup, lemon juice, and egg white in a cocktail shaker. Secure lid and shake vigorously for 30 seconds or until foamy. Add ice to the shaker and shake again for 15-20 seconds.
Strain into a coupe glass and garnish with a fresh flower, lemon peel or rosemary sprig. Enjoy!