Step 1

Muddle the sugar, mint and lime in the bottom of a glass with the end of a wooden spoon (I use a wooden pestle) until the sugar has completely dissolved.

Step 2

Add the grapefruit juice, and stir together. Top up the glasses with sparkling water or club soda and one or two large ice cubes.

Step 3

Garnish with a few sprigs of mint leaves and slices of lime.