Place flour on a large plate. Toss lamb in flour, shaking off excess. Transfer to a plate. Heat half the oil in large heavy-based saucepan over medium-high heat. Cook lamb, in batches, for 3 minutes each side or until browned. Transfer to a plate.
Heat remaining oil in pan. Add onion, carrot and celery. Cook, stirring, for 5 minutes or until vegetables are just tender. Add garlic. Cook, stirring, for 1 minute or until fragrant.
Stir in stock and tomatoes. Return lamb to pan. Cover. Bring to the boil. Reduce heat to low. Simmer for 30 minutes. Remove lid. Simmer for 30 minutes or until lamb is cooked through.
Stir in oregano and olives. Season with pepper. Serve with bread.