Cook couscous as directed on package. Season chicken with 1/4 teaspoon salt and 1/4 teaspoon pepper. In a nonstick skillet, heat oil over medium heat. Cook chicken, turning once, 2 minutes per side. Transfer chicken to a plate. Cook onion in same skillet, stirring occasionally, 5 minutes. Add garlic and tomato paste; cook, stirring, 1 minute more. Add tomatoes, cumin and cinnamon; cook, stirring, 2 minutes more. Return chicken to skillet; add chickpeas, broth, zucchini, remaining 1/2 teaspoon salt and remaining 1/4 teaspoon pepper. Simmer, covered, until chicken is cooked through, about 10 minutes. Serve stew with couscous. Garnish with cilantro.