Make a syrup with the sugar and water by placing into TM bowl and cooking 5 min/80°C/speed 2. Cool and freeze into ice cubes over night.
When you are ready to make the sorbet, place all ingredients including the frozen syrup and cucumber into TM bowl and blend 2 min/speed 10 with the aid of your Thermomix spatula through the hole in the lid.
Serve immediately. It can be refrozen but will get quite solid, (unless you add a dash of gin to the mixture!)