Halve the melon and scoop the seeds out from 1 half. Scoop the flesh out from that half and add it to the blender. Roughly chop the cucumber and the celery sticks and add them too.
Slice the skin from the lemon. Roughly chop the lemon flesh and add to the blender. Peel and grate the ginger into the blender. Tip in a few ice cubes and trickle in 250ml water. Whizz together till smooth and serve.
Small but mighty You'll need a large blender to make this smoothie. If yours is a little smaller, blitz the melon and celery with half the water and pour it into a jug. Then blitz the cucumber, lemon and ginger with the rest of the water. Stir into the melon smoothie and serve.
Extra, extra You can use all the melon in this smoothie if you like (and have a really big blender) or use it in a refreshing salad with chopped tomatoes, sliced spring onions, chopped mint and coriander and a vinegar and olive oil dressing.