TO ORDER Chill a flute, coupe or coupette by filling with ice. Put the rum, lime juice and demerara sugar syrup (see tip) in a little jug with the leaves from the mint and a couple of ice cubes, then stir to chill the mixture. Remove the ice from your glass, then pour in the drink through a sieve, putting a couple of pretty mint leaves back in. Top up with the fizz of your choice and serve.
BATCH IT The day before, batch up the rum, lime juice and sugar syrup if you want to be able to make multiple drinks at once.
Demarara sugar syrup
Mix two parts demarara sugar to one part boiling kettle water in a small pan, then stir over a medium heat until dissolved. Cool, then bottle.