Prepare three cocktail glasses, add half of the ice cubes to the glasses. Squeeze the juice out of the limes and peel the zest. Put the mint leaves on one hand and clap, this will release the aroma.
Add 2 tablespoons of ice cubes, lime juice, elderflower cordial, crushed mint leaves and white rum to a mixing glass. Shake it well, using a cocktail shaker or stir well, using a bar spoon.
Divide the liquid between three glasses, filled with ice cubes. Add a splash of carbonated water, stir well, add the remaining ice cubes and garnish with a sprig of mint and lime zest. Enjoy.