Heat the oil in a frying pan on the hob and lightly fry the pork and onion for 5 minutes until beginning to brown. Transfer to a casserole dish. Add the mushrooms to the pan and fry for 5 minutes, then add to the casserole.
Stir the thyme, cayenne, chicken stock and pineapple and its reserved juice into the casserole. Bring to the boil and pour over the pork. Cover the dish with foil and place on the lower rack of the halogen oven.
Set the temperature to 200°C (392°F) and cook for 25 minutes or until the pork is tender. In a small bowl, blend the cornflour with the measurement water. Using a slotted spoon, remove the pork from the casserole and stir the cornflour paste into the liquid. Season to taste with salt and return the pork to the dish. Cover and cook for a further 5 minutes. Serve hot with steamed rice.