Rhapsody in Green

Prepare fennel-infused gin with 750 ml London dry gin and 1 cup fresh fennel fronds and tender stems. Cover, stand at room temperature for 12 hours, strain, bottle and refrigerate. Muddle the listed sage and mint, add all measured liquids and ice, including exactly 3 dashes celery bitters, stir and double strain into a chilled cocktail glass. Express the lemon peel and discard it, then finish with the fennel sprig.