Preheat the oven to 100°C and dry plum halves on a tray for two hours.
Preheat the oven to 220°C and flatten the pork loin on a work surface.
Season three-quarters of the plums and roll them inside the pork loin, securing with string.
Chop remaining plums and brown the pork bones in a roasting pan with rapeseed oil.
Crisp the pork skin in a frying pan with vegetable oil for 8 minutes.
Rest the pork on the bones with tomato, garlic, and thyme and roast for 30 minutes.
Add water and Madeira, reduce heat to 180°C, and roast covered for 35 minutes.
Remove the meat to rest for 30 minutes and strain the pan juices into a casserole.
Simmer the juices with chopped plums and serve over sliced pork.