Add the sugar and water to a pot, stir gently over a medium heat to dissolve the sugar. Bring to the boil and cook until the sugar syrup is a pale golden colour. Pour over the cashew nuts laid out on a silicone sheet. Allow to set, then chop up in a food processor or with a sharp knife or a pestle and mortar.
Halve the papayas and scoop out the seeds with a teaspoon. Scoop a little of the flesh out into a bowl, leaving the skin and a layer of flesh in tact.
Take a vegetable peeler and peel the cucumber into ribbons, discard the watery middle bit. Use the same method for the carrots.
Toss together the carrots, cucumber, papaya, sesame seeds, coriander and dressing.
Fill the papaya cavities.
Garnish with alfalfa sprouts and chopped cashew nut brittle.