3 slices fennel, sliced thinly
1⁄2 oz. fresh lemon juice
1⁄4 oz. simple syrup
2 oz. fresh grapefruit juice
1 1⁄2 oz. mezcal
Muddle fennel with lemon juice and simple syrup in a cocktail shaker. Add grapefruit juice, mezcal, and ice; shake vigorously. Strain into a chilled coupe or martini glass; garnish with a fennel frond.