Blue Dahlia is delectable very strong cocktail at 2.1 standard drinks. Shaken with 45ml vodka and 15ml maraschino liqueur with 10ml bitters grapefruit abc as well as 10ml lime juice including 10ml sugar syrup also 100ml ice and best with lunch. Just add blueberries to glass then add ice to shaker and add all ingredients to shaker, less herbs. Shake well and strain into glass over blueberries and garnish with herbs and served in a saucer glass cold.