In either a large freezer or a baking dish add the diced pork, wine, prunes, olives, capers (and the juice they came in), dried oregano, salt and pepper. Seal the bag (or wrap the baking dish in cling film), then marinade overnight in the fridge.
Take out of the fridge a couple of hours before it goes in the oven, so can come to room temperature throughout.
Pre-heat the oven to 150ºC fan.
Put the marinated pork into a large casserole dish with the chicken stock. Stir together, put the lid on cook in the oven for 2 hours.
The pork should be soft and tender. Sprinkle with fresh oregano and serve with your choice of carbs.