First the cucumber quarter is cut lengthways into eighths and 7/8 of this is finely pureed in a blender with a sprig of mint, the lime juice and 4 cl of still water. Then put 8 cl of the cucumber puree in a long drink glass and mix with 2 cl sugar syrup. Now add crushed ice, fill up with 15 cl of sparkling water and stir thoroughly.
Divide the cucumber again lengthways and then place a piece with a sprig of mint in a glass as a decoration.