Place the rice noodles in a bowl, pour boiling water over and leave to stand for approx. 10 mins. Add the mange-tout approx. 5 mins. before the end, drain, briefly dip in ice-cold water, drain.
Puree the reserved melon pieces with all the ingredients up to and including salt in a blender and pour the sauce into a bowl. Add the rice noodles and mange-tout to the sauce along with the melon balls, cucumbers and spring onion, mix together. Scatter the peanuts, chilli and coriander over the top.