Preheat the oven to 170ºc. Place a large casserole over a moderately high heat and brown the oxtail pieces in the oil for 8 mins or until browned on all sides. Transfer to a plate.
Add the carrot, celery and onion and cook for a minute or until lightly browned. Add the oxtail, along with the wine, stock, tomatoes and rosemary. Bring to the boil, cover with a lid and place in the oven for 2 hours or until the meat is soft, then remove the lid and cook for a further hour or until the meat if falling off the bone. Skim off any fat and season with salt and pepper.
Sprinkle the gremolata on top and serve with broccolini and smashed cannellini beans.
To make the gremolata: Mix the ingredients together in a small bowl.
