Place noodles in a bowl, cover with boiling water and allow to stand for 5-6 minutes or until soft.
Cook the beans in boiling water for 2 minutes or until bright green. Drain, cool under cold water and drain again. Combine with the noodles, cucumber, mint, coriander, peanuts and chilli.
To make the dressing, combine the lime juice, fish sauce and sugar and pour over the salad. Serves 8.