Preheat the oven to 150C/135C fan oven. Place around 4 tbsp flour in a large bowl and season generously. Toss the oxtail pieces in the flour to coat. Heat 2 tbsp oil in a large ovenproof casserole and brown the oxtail over a high heat until coloured all over. Remove and set aside in a dish. Lower the heat and fry the onion and celery until soft and golden. Add the garlic and cook for another couple of minutes, then pour in the wine. Scrape up all the bits that have stuck to the bottom of the pan. Return the oxtail to the pan. Juice the orange and add to the pan along with half of the orange itself, cut into two pieces. Add the oxtail soup powder diluted with warm water, bay, cinnamon, ginger, juniper and star anise. Season well. Cover with a lid and bring to the boil, then put in the oven and cook for around 3 hours until the meat is falling off the bone. Check every now and again to make sure the meat is still mostly submerged in the liquid – if not, top up with a little water. After 2 hours, add the dates and shallots to the pan, stir, and return to the oven for the remainder of the cooking time. When ready to serve, check the sauce is the desired consistency – if it’s too runny, remove the oxtail from the pan and reduce the sauce by boiling it. Try to fish out the bay leaves, anise, cinnamon stick and orange peel before serving. Check the seasoning and add the sugar if it needs it. Scatter over the parsley and serve the meat accompanied by the sauce.