Melt butter in a large pan over low heat.
Add cabbage and garlic, cover, and cook until soft.
Add wine, port, and bouquets, then simmer for one hour.
Preheat the oven to 180°C.
Cut pork into equal pieces and season with salt.
Heat oil in an ovenproof pan and sear meat on all sides.
Transfer pan to oven and cook for six minutes.
Melt butter in a frying pan and fry shallots until coloured.
Add sugar and thyme, frying until caramelised.
Pour in stock and cook until shallots are tender and glazed.
Cover cooked meat with foil and rest.
Blend cabbage into a smooth puree using a food processor.
Serve pork with cabbage puree and glazed shallots.