Trim the fat from the chops, leaving just a narrow border. Slash the remaining fat at intervals to prevent the chops curling. Season with pepper, bring to room temperature, then season with salt and more pepper.

in a large frying-pan, heat the butter and olive oil. When foaming subsides, brown the chops 2 at a time on both sides and transfer to a flameproof casserole.

Add the sliced onion to the frying-pan and saute gently, stirring frequently, for 2-3 minutes until transparent.

Stir in the remaining ingredients, add 300 ml (10 fl oz) water and season with salt and freshly ground black pepper. Bring to the boil, stir to remove the sediment from the base of the pan and pour over the chops. Reduce the heat, cover and simmer gently for 1 hour or until the chops are tender, turning them from time to time. Serve.