Preheat the oven to 180° Celsius.
In a large oven proof pan, brown the oxtail.
Season with salt and pepper.
Add the tomato puree and cook for another 2 minutes.
Remove from the dish and set aside in a bowl.
In the pan melt the butter and fry the onion, leak and celery until soft.
Add the carrots and then remove from the pan and add to the oxtail.
Add the red wine to the pan.
Add the oxtail and the vegetables and all the juices.
Add the garlic, thyme, parsley, tin of tomatoes and the coke.
Place the casserole in the oven for at least 3 hours.
Adjust the seasoning if necessary.
Remove from the heat and when cool place in the refrigerator overnight.
Remove the fat from the top and reheat – make sure there is enough liquid to cover the meat at all times
Serve with a mix of brown and wild and white rice