Thai-style Green Bean Salad

The Thais enjoy a native plant called winged bean. It is a delicately flavoured vegetable that has a hint of asparagus. The beans are bright green and have a decorative frill on each side, hence their name. A popular way to enjoy them in Thailand is to blanch them, toss them in an aromatic dressing and serve them as a salad. The Thais combine these beans with prawns and chicken; I have made a vegetarian version of this tasty dish. If winged beans are unavailable, you can substitute runner b