Soak the tamarind in the water.
Put the meat into a bowl with the fish sauce, mix and leave to stand for 10 minutes.
Heat the oil in a large frying pan and brown the meat on all sides in batches.
Add the onions and fry until soft.
Add the bay leaf, peanuts and raisins and fry briefly.
Stir in the coconut milk and stock, followed by the curry paste.
Cover and simmer for 20 minutes.
Squeeze out the tamarind, discard the fibres and add the liquid to the curry.
Add the chili and simmer for a further 15 minutes, until the meat is tender.
Add salt and sugar to taste.
Strip the coriander leaves from their stalks and shred.
Sprinkle over the curry.