Trim the lamb and cut it, tomatoes, potatoes and carrots into dice. Cut the courgettes and celery into thin slices.
In a large heatproof casserole, combine olive oil and butter (or smen). Add lamb, onion and tomato, and sauté, stirring constantly, for 3 minutes. Add black pepper, cinnamon, hot and sweet red peppers, saffron and salt and continue to cook,