Steam pork until well cooked. This will take 30-60 minutes depending on your steamer and the cut of meat so check for an internal temperature of 70C (155F) with a meat thermometer and remove at that temperature.
Allow to rest 10-15 minutes at room temperature and then place in refrigerator a while to cool.
While pork is cooling you can make the paste by adding all the paste ingredients one by one to a mortar and pestle and pounding until smooth. Set to one side.
Mix fish sauce and oyster sauce in a small and then mix in the palm sugar until dissolved if using soft palm sugar, or otherwise just break solid palm sugar into a few pieces because it will dissolve later in the wok.
Cut pork into cubes of around 1cm (1/2 ).
Deep fry the pork over moderate heat until nice and golden, remove and drain.
Add a little of the left-over oil from deep frying to a wok over moderate heat and stir fry until golden in colour and fragant.
Add sauce / sugar mix to wok and lightly stir once or twice until it has become sticky.
Reduce heat, add pork and simmer a few minutes until coated. The meat will become tough if you leave it too long.
Serve sprinkled with deep-fried shallots and coriander leaves.