Heat a large saucepan over a low heat and spray lightly with oil.
Add onion, garlic, celery and carrots and cook gently for a few minutes until soft. Add lamb and rosemary and cook until the meat is browned on all sides. Cover with Napoli sauce and cook for a further 2 minutes. Add the chicken stock and bay leaves and bring to the boil.
Add the barley and reduce heat. Cover and simmer gently for 1 1/2 hours until the barley is tender. Add beans and simmer for another 30 minutes until tender.
Remove the bay leaves and rosemary sprigs and serve sprinkled wit parsley.