Remove all fat and gristle from the lamb and cut it into equal cubes. Peel, wash and thickly slice the potatoes. Cut the onions into rings. Scrape, wash and slice the carrots.

Cover the base of a casserole with sliced potato, cover with half the lamb, then add half the onions and carrots. Sprinkle with salt and the thyme.

Fill the casserole with further layers of onion, carrot, potato and lamb, pour in the stock and cook in a moderate oven (180°C, 350°F, gas 4) for about 1 1/2 hours.

Half way through the cooking time check that there is enough liquid in the casserole, and add more chicken stock or water if necessary. The potatoes should fall slightly into the stock during cooking to make a thick gravy. Sprinkle with parsley before serving.