Blanch the trotters in boiling water for 2 minutes, remove and set aside.
Heat the oil in a large pot to 140 degrees C. Add the sugar and rock sugar; stir until the mixture turns light brown.
Add the hot chilli paste and stir for 1 minute. Add the ginger, star anise, cinnamon and stir-fry until fragrant.
Add the five spice powder, salt, spring onion and chicken stock granules and stir well. Then add the pork stock and bring to the boil.
Add the trotters to the pot and bring to the boil over medium heat. Turn the heat down to low. Cover the pot and simmer for 80 minutes or until the skin becomes soft an tender. During the cooking time, turn the trotters occasionally so they don't stick to the pot.
Turn off the heat and keep the trotters in the sauce for an additional 15 minutes to allow the flavours to permeate. Transfer to as serving dish and pour the sauce on top.
Pigs' trotters can be purchased at your local butchers. You may need to place a special order for them.
Rock sugar can be purchased in Chinese/Oriental speciality shops or online.