Season the chicken with salt. Heat the olive oil in a Dutch oven and brown the chicken on both sides.
Add the onion, carrots, spices, and stock. Cover and simmer for 25 minutes, then add the zucchini and chickpeas and simmer until the chicken is tender, about 15 minutes more.
Prepare the Couscous:
Place the couscous, olive oil, raisins, and a pinch of salt in a bowl. Pour over 2 cups of hot broth from the Dutch oven, cover, and rest for 10 minutes.
Fluff the couscous thoroughly with a fork and adjust seasoning.
Assemble and Serve:
Spread the couscous on a large platter. Arrange the chicken and vegetables over the top, spoon over some broth, and garnish with cilantro.
Serve hot with extra broth and harissa at the table.
Notes
Keep the couscous covered while it hydrates.
Add zucchini later so it stays intact.
Offer harissa separately so everyone can adjust the heat.