Muddle the mint leaves, sugar, lemon slices and lime slices with a muddler or pestle in the bottom of a large glass. In a blender, mix a little ice, water, coconut milk, lemon juice, lime juice and rum (if using). Give drink a quick blend. Pour into glass with muddled mint mixture. Garnish with mint sprigs and lime slices.
Recipe courtesy of Ingrid Hoffmann