1.Place noodles in medium heatproof bowl, cover with boiling water; stand until just tender, drain.
2.Cook chilli, garlic, lemon grass and ginger in oiled large saucepan, stirring, until fragrant. Stir in stock and the water; bring to the boil.
3.Add chicken; return to the boil. Reduce heat; simmer, uncovered, skimming occasionally, about 5 minutes or until chicken is cooked through. Add noodles, mint and sauces to soup; stir until hot. Just before serving, sprinkle with coriander.
Dried mung beans are ground into flour to make bean thread noodles. These very fine, almost transparent noodles are also known as bean thread vermicelli, or cellophane or glass noodles.