Using a sharp knife, trim all the fat and cartilage from the lamb, then cut the meat into 2.5cm (1in) cubes.
In a flameproof casserole, heat 1 tablespoon of the oil over moderate heat. Add the onions and garlic and sauté for about 10 minutes or until well browned. With a slotted spoon transfer to a plate.
Heat the remaining oil in the casserole over moderately high heat. Add the lamb and sauté, stirring, for about 3 minutes or until well browned on all sides. Sprinkle the flour and rosemary over the meat and cook for a further 11⁄2 minutes or until the flour is absorbed.
Return the onions to the casserole together with 225ml (8fl oz) stock and the tomato juice. Bring to the boil, then cover and simmer gently for 1 hour. Stir in the chickpeas. Cook, covered, for a further 1–1 1⁄4 hours or until the lamb is almost tender.
Stir in courgettes, tomatoes, pepper and basil. Add more stock if the stew is becoming too thick. Cook for about 15 minutes longer or until the lamb is very tender when pierced with a fork. Serve hot.