How to Make It
Preheat the oven to 350°. Season the chicken with salt. In a large, deep ovenproof skillet, heat the olive oil until shimmering. Cook the chicken, skin side down, over moderately high heat until the skin is browned all over, about 8 minutes. Transfer the chicken to a plate and spread the skin side with the harissa.
Add the olives, preserved lemon peel and garlic to the skillet and cook over low heat until fragrant, about 30 seconds. Add the couscous and stir until coated with oil. Add the chicken broth and season with salt. Nestle the chicken in the couscous skin side up.
Bring the broth to a simmer. Cover and bake in the oven for about 25 minutes, until the chicken is cooked through and the couscous has absorbed the broth.
Transfer the chicken to plates. Fluff the couscous with a fork and season with salt. Spoon the couscous beside the chicken, sprinkle with cilantro and serve.