Oxtail can take anything from 1-2 hours to cook – in a pressure cooker, however, it takes only about one hour, and you'll find there are no fumes in your house, either.
1.5 kg oxtail, cut into 2-3cm thick pieces and trimmed of any excess fat
1 onion, peeled and finely chopped
2 cloves of garlic, peeled and crushed
1tsp fresh thyme leaves
80g butter, plus more for the carrots
70g flour, plus a little extra for dusting
2tsp tomato purée
200ml red wine
3 litres beef stock or a couple of good-quality stock cubes, dissolved in 2 litres of hot water
Salt and freshly ground black pepper
1 large or 2 small heads of celery
Preheat the oven to 220C/gas mark 7. Season the pieces of oxtail and lightly dust them with flour. Roast in the oven for 30 minutes, turning them halfway through to make sure they're nicely coloured on both sides.
Meanwhile, heat 60g of the butter in the pressure cooker pan and gently cook the onion, garlic and thyme for 3-4 minutes until soft, stirring every so often. Add the flour and tomato purée and stir well. Gradually add in the red wine and stock, stirring well to avoid lumps forming, and bring to the boil. Add the pieces of oxtail then close and secure the pressure cooker lid.
Cook on the lowest heat for 45 minutes then remove from the heat and release the pressure and remove the lid. Check the pieces of oxtail. The meat should be tender and easily removed from the bone; if not, replace the lid and cook for another 15 minutes or so.
If you haven't got a pressure cooker, allow up to 2 hours to cook the oxtail in a covered pan on a low heat preferably with a simmering plate. Check after one and half hours to see if it's tender. Remove the oxtail pieces and put to one side.
Skim the fat from the sauce in the pressure cooker with a ladle (if the sauce is not thick enough, drain it off into another pan and simmer until it thickens, skimming every so often).
Meanwhile, remove any excess root from the celery, but not too much as you want it to remain intact, then trim it to about 8-9cm in length and keep the trimmings for a stock or soup (see the following oxtail broth recipe). If the outer stems are stringy, then carefully peel them. Cut the celery into 4 lengths and place in the oxtail sauce. Put the lid back on the pressure cooker and close it and cook for 15 minutes.
Remove the celery and keep warm, return the pieces of oxtail to the pressure cooker and reheat for 4-5 minutes. Spoon the oxtail and sauce into bowls with the celery. Reserve any extra sauce for the soup below.