In a tumbler half-filled with ice cubes, stir in 50ml Trinidadian dark rum (such as Angostura Single Barrel Reserve), the juice of half a lime, a shake or two of rhubarb bitters (angostura may be substituted), a dash of Monin coconut syrup (or substitute with a coconut liqueur) and top with freshly pressed rhubarb and apple juice. Serves 1.

To serve a crowd, simply multiply up the quantities and serve in a large jug or punch bowl half-filled with ice.