- Preheat the oven to 200 degrees C. Arrange all the vegetables and garlic in a large shallow roasting tin. Drizzle with the olive oil and season well with black pepper.
- Roast the vegetables for 45–50 minutes, turning them occasionally, until tender.
- Meanwhile, put the couscous in a deep ovenproof dish, pour over 2 cups of boiling water, cover and leave for 5 minutes to allow the grains to soak up the water. Cover tightly with foil and put in the oven with the vegetables for their final 15 minutes, to keep warm.
- Fluff up the cooked couscous with a fork, stir in the butter and herbs and season to taste. Serve the roasted vegetables piled on top of the couscous. Sprinkle with harissa or chilli sauce, to taste.
Harissa is a fiery North African sauce made from a mixture of red chillies, garlic, coriander, cumin, caraway, mint and olive oil. You'll find it in larger supermarkets or you can use any chilli sauce or spicy tomato sauce.