Step 1

First, juice the grapefruits and make the honey simple syrup. Pour the honey and water into a small saucepan and warm over medium heat. Use a whisk to blend the honey into the water and remove from heat (there is no need to bring the mixture to a simmer, this process should only take a couple of minutes).

Step 2

Fill a small cocktail shaker with ice. Pour in the grapefruit juice, vodka, lemon juice and honey simple syrup. Top with a sprig of rosemary and a dash of salt. Put on the lid and shake until the mixture is thoroughly chilled, about 20 seconds. Strain into a martini glass and garnish with a small sprig of rosemary. Serve immediately.