Heat the oven to Gas 4, 180ºC, fan 160ºC. Season the lamb first, then heat the oil in a large, flameproof casserole dish and brown the lamb on all sides.
Reduce the heat and add the onion to the pan. Saute until golden. Stir in the garlic cloves, tomatoes, chickpeas, thyme, and half the stock and bring to a gentle simmer.
Cover and place in the oven for 2 hours, stirring occasionally. Add more of the stock if necessary. After 1 hour add the olives and anchovy puree.
Remove the lamb and slice before serving. Serve with the cooking sauce on the side.
See more lamb recipes
For top tips on protecting you and your family when preparing raw meat and poultry, visit Food Safety in the Home and view the full Food safety at home video.