Comet Rocket is delectable quite strong cocktail at 1.4 standard drinks. Shaken with 45ml gin and 10ml blackberry syrup with 35ml tonic water as well as 100ml ice and best with an entree or small snack. Just add half the ice to shaker then place mint leaves into shaker and pour in the gin and syrup. Vigorously shake and stir in the tonic soda water and served in a old fashioned glass cold.