First make the red harissa which will be the marinade for the chicken by adding the spices to a small frying pan and frying gently until they begin to give of an aroma, put them in a pestle in mortar and ground finely.
Next add the rest of the ingredients to a pan with some olive oil and fry for about ten minutes until the ingredients go a darker colour. Add this mixture with the spices to a blender and finely blend before adding the yoghurt and then mixing with the chicken to marinate overnight (or at least for an hour).
Place couscous in a large bowl. Pour over about 425ml hot chicken stock. Stir once and leave to stand for 10-15 mins then add the tomato, coriander, drained chickpeas, pomegranate seeds and red onion.
When ready to cook remove the chicken from the marinade and pan fry on each side for a couple of minutes to colour the meat. Add the marinade and cook for about ten minutes each side on a medium heat until the chicken is cooked through. The marinade will become a thick and silky sauce for your dish.
Serve with the cous cous and a spoonful of yogurt and coriander to top.