Makes one cocktail. Cocktail Credit: The Charred Cask
Add whisky, liqueur, simple syrup and fresh herb (choice of lavender, rosemary or thyme) to a shaker and lightly muddle. Add ice and shake well. Strain into a rocks glass over ice. Add a splash of grapefruit juice and fill the glass the rest of the way with seltzer. Garnish with herb of choice.