Semi-puree the onion in a blender and cook gently with 2 tbsp of olive oil in a large pan (or wok) for 5 minutes.
Add the ras-el-hanout paste and mix well. Cook for a further minute.
Add the tomatoes with their juice and water along with 1/2 tsp salt and a dash of black pepper. Then add the carrot and courgette. Bring to the boil and simmer for 10 minutes.
Pre-heat the oven to 175°C.
Add half of the chickpeas to the pan. Blend the remainder with their juice and add to the stew. Simmer for a further 10 minutes. Season as required.
Cover the cous cous and 1/2 tsp salt with boiling water in a heat-proof bowl. Wait 3 minutes or until the water has been fully absorbed and fluff up with a fork and 2 tbsp olive oil.
Add the stew to a 12 x 10 inch baking dish and cover with the cous cous, spreading evenly.
Cook in the oven for 30 minutes or until the cous cous is slightly browned.
Allow to stand for 2 minutes before serving as part of a main meal.
If you'd like to make your own Ras-el-Hanout there's a great recipe over at Epicurious.
Some Ras-el-Hanout mixtures or brands can be quite hot. Adjust to your own taste.
Ras-el-Hanout is a North African spice most commonly associated with Morocco but, in fact, used in many countries of the Western Maghreb. It is commonly held that it should have exactly 12 ingredients. It's name means 'Head of the Shop' or, roughly translated, 'top-shelf' or 'the finest'. Spice sellers often make slight changes to their recipes depending upon who's buying. Either way, this spice is designed to be the 'best quality' product. Find out more about Ras-el-Hanout at The Epicentre.