Swap the fish sauce,
lime juice, star anise and sugar for a sachet
of miso soup or 1 tbsp miso paste.
Boil the noodles until al dente, then drain.
Put the stock in a pan with the fish sauce,
lime juice, star anise and pinch of sugar.
Bring to the boil and add the noodles and
prawns. Warm through, then pour into
a bowl and serve topped with the mint,
coriander and chilli.