Muddle nectarine and rosemary with the simple, add remaining ingredients except soda. Shake, strain over fresh ice into a Collins glass, top with soda, garnish.
The result is a harmonious marriage of the nectarine and rosemary. The Campari and Gin add bitter and herbaceous notes, giving it backbone. Though the 3/4 simple may seem generous, the drink is definitely not overly sweet. NOTE: These recipes with muddled fruit work much better with a Boston Shaker and a four prong strainer, with a mesh strainer below as you pour into the glass. A capped cocktail strainer will clog.