1 Preheat the oven to 200°C. Peel the butternut, halve it and cut into thin wedges. If you’re short of time, buy sliced butternut and cut into smaller pieces to reduce the cooking time.
2 Mix the butternut and onion with the oil then season with sumac, salt and pepper and bake for 30 minutes. Turn the wedges over and roast for another 5–10 minutes; make sure they are caramelising and not burning.
3 Steam the couscous according to the instructions on the packet until done. Beat the salad dressing ingredients together.