Melt the butter in a large pan over a low heat. Add the cabbage and garlic and cover with a lid. Cook until the cabbage is soft then add the wine, port and bouquets and simmer for about an hour until the cabbage is really soft.
Preheat the oven to 180C/350F/Gas 4. While the cabbage is cooking, cut the pork into equal sized pieces and season with salt. Heat the vegetable oil in an ovenproof pan, put the meat into the pan and seal all over. Transfer to the oven and cook for six minutes.
Meanwhile, melt some butter in a frying pan and fry the shallots until they start to colour. Add the sugar and thyme and continue to fry until the shallots are caramelised then pour in the stock and cook until the shallots are tender and the stock has reduced to a sticky glaze.
When the meat is cooked, remove from the oven, cover with foil and leave to rest. Remove the cabbage from the heat, transfer to a food processor and blend to a smooth purée.
To serve, place the pork on a plate with a spoonful of the spiced cabbage purée, the shallots and some of the glaze.