Put sugar in a saucepan and bring to boil, turn heat down a bit
and cook until it turns a golden brown - be careful not to leave
it too long or it will burn. As soon as it goes golden brown, take
off the heat and add the fish sauce all at once, and return to gentle
heat, stirring until dissolved.
Put the pork slices in a clay pot (or another saucepan) and pour
over the caramel sauce, and add the water, soy, shallots and chilli.
Bring to the boil, put on lid, and simmer gently for an hour or
so, until the pork is really tender.
Serve with boiled rice.