Heat 1 tbsp oil in a non-stick frying pan or skillet and brown the pork over a high heat for 10-12 mins or until the cubes are well caramelised. Use a slotted spoon to remove the pork from the pan and set aside. Tip out almost all of the oil, reserving just enough to fry the onion and garlic.
Turn down the heat slightly and fry the onion, garlic and bay leaves for 5-6 mins or until aromatic and translucent. Return the pork to the pan and add the vinegar, soy, sugar, peppercorns, white pepper and 250ml water. Bring to the boil, then turn down to a simmer, cover and cook for 50 mins.
Meanwhile, in another pan, melt the remaining oil over a medium heat and caramelise the pineapple for 5-6 mins or until there is a golden crust on each chunk – you may need to do this in batches. Add the pineapple to the pork once the meat is cooked (along with 50ml water if it looks a little dry) and cook for a further 20 mins, uncovered, until the sauce is thickened. Serve with rice.