First you’ll need to soak the cannellini beans. Either place them in a pan with 4 pints of cold water and bring them up to the boil for 10 minutes, then remove from the heat and leave to soak for 2 hours; or else soak them in cold water for at least 6 hours (overnight is best).
Place the seasoned flour in a polythene bag and add the oxtail pieces. Shake until well coated, then remove, dusting off any excess. Heat the oil in a large casserole with a lid and gently brown the oxtail pieces in batches. Using a slotted spoon, transfer to a colander and allow the excess oil to drain off.
Add the onion, carrots and celery to the pan and sauté for 10 minutes until softened but not coloured. Add the garlic, thyme and bay leaves and continue to cook for a minute or two. Deglaze the pan with a little of the red wine, scraping the bottom of the pan to remove any sediment, then pour in the remainder with the stock, tomatoes, tomato puree and Worcestershire sauce. Season to taste.
Return the oxtails to the pan with the soaked beans. Bring to the boil, then cover and simmer gently for 3½ hours until the meat is coming away from the bones and some of the fat from the oxtail has bubbled up to the top. Skim away the fat and season to taste. Scatter over the parsley and serve directly on the table with a separate dish of the sautéed cabbage.