2.5-cm (1-inch) piece of fresh root ginger, peeled and finely chopped
1 garlic clove, finely sliced
1 green chilli, deseeded and finely sliced
200 ml (7 fl oz) coconut milk
2 teaspoons Thai fish sauce
300 ml (1/2 pint) vegetable stock
1 kg (2 lb) mussels, scrubbed, and any unopened shells discarded
1 small bunch of coriander, roughly chopped, to garnish (optional)
Heat the oil in a large saucepan or casserole, and cook the shallots, ginger, garlic and chilli gently for 6–8 minutes, until really soft.
Add the coconut milk, fish sauce and stock, and heat to boiling point. Simmer gently for 5–6 minutes to allow the flavours to develop, then stir in the mussels. Cover with a tight-fitting lid and leave to cook gently for 4–5 minutes, shaking the pan occasionally, until all the mussels have opened, discarding any that remain closed.
Spoon into large, shallow bowls with the coconut-flavoured soup and serve immediately scattered with coriander, if using.