Put the curry paste, cumin seeds,
turmeric, coriander seeds, lemon grass, sugar and tomatoes in a mortar
and pound, or process in a small food processor to make as smooth as
paste as possible.
Heat the oil in a large wok. Stir fry the
garlic, shallots and chilies for 2-3 minutes.
Add the spice paste and continue to stir
fry for 3 minutes, then add the coconut milk, fish sauce and lime
leaves.
Mix well and simmer for 5 minutes.
Finally, add the shrimps, stirring and
then the mussels.
Cover and simmer for a few minutes, until
all the mussels are open.
Garnish with coriander leaves and serve
with rice.