1.In a large heatproof bowl, cover noodles with boiling water; separate noodles with fork, drain.
2.Divide noodles, peas and coriander between four serving bowls.
3.Bring 3 cups (750ml) water and soup mix to the boil in medium saucepan.
4.Add prawns and bok choy to soup; simmer until prawns change colour. Ladle broth into bowls.