Use a sharp knife or mandoline to thinly slice ¼ cup of celery stems and leaves. Set aside. To your shaker add the celery, ¼ cup arugula. Add ½ oz simple syrup and ½ ounce of fresh lime juice and muddle together until thoroughly bruised. Add 2 oz of Bombay Sapphire Gin and ice. Shake until very cold. Double-strain into a coupe glass and garnish with lime or an arugula leaf.