Season the lamb with salt and pepper. Heat the oil in a frying pan on the hob and fry the lamb until browned. Transfer to a casserole dish.
Add the onions, carrots and green pepper to the pan and fry for 5 minutes to soften. Stir in the garlic, tomatoes, sugar and spices. Season with a little salt and pepper. Bring to the boil, then tip the contents of the pan into the casserole dish. Stir in the dates. Cover the casserole dish with foil and place on the lower rack of the halogen oven.
Set the temperature to 200°C (392°F) and cook for 45 minutes or until the lamb is tender.
Meanwhile, towards the end of the cooking time, put the couscous and bouillon powder in a heatproof bowl, stir to mix and pour over the measurement boiling water. Cover and leave to stand for 10 minutes until the water has been absorbed. Fluff up the couscous with a fork and serve with the lamb.