Oxtail casserole

1) Preheat the oven to 160C/gas 3.
2) Mix the flour with salt and black pepper in a bowl.
3) Place a large, oven proof casserole pot over a high heat and add the oil.
4) Pat the oxtail dry with kitchen paper. Toss the pieces in the seasoned flour and add to the pot one by one and brown on all sides. This may need to be done in batches.
5) Remove from the pan and set aside on a plate.
6) Add some more oil to the pot, reduce the heat and add the onion, carrot and celery. Fry for 4-6 minutes until just tender.
7) Stir in the tomato purée, mustard and Worcestershire sauce until evenly combined.
8) Add the red wine, beef stock, balsamic vinegar, rosemary and thyme. Season with salt.
9) Cover with a lid cook in the oven slowly for 3½ hours or until the meat is falling away from the bone.