Cut the onion and red pepper into 4 wedges. Scatter them in a baking tray, then drizzle with some oil. Bake for about 15 minutes, then let them cool, then remove their skins and cut them into thin slices.
Put the couscous in a heat-proof bowl. Add one cup of boiling water, the cumin powder & harissa paste, cover with a plate for 10 minutes. Loosen the couscous with a fork and add a pinch of cinnamon and ground pepper to your liking. Taste and some salt, if needed.
Mix in the roasted veggies, chickpeas, grated carrot and salad leaves.
Make the tahini sauce, then pour it over the salad. Combine well before serving.