Start by making the rosemary simple syrup. Boil water and slowly stir in sugar. When sugar is dissolved remove from heat, add minced rosemary and refrigerate for 45 minutes. Then strain the rosemary out of the simple syrup. Simple syrup will keep for two weeks, refrigerated.

Combine 3/4 oz rosemary simple syrup, lemon juice, gin and ice. Stir with a cocktail stirrer and top off your rocks glass with club soda and the rosemary sprig.