In a pot over medium-high heat, soften the leek in the oil for 5 minutes or until translucent. Add the carrots, cranberries and ground fennel. Cook for 1 minute, then add the chicken broth. Season with salt and pepper and bring to a boil. Remove from the heat and add the couscous. Cover and let rest for 5 minutes. Fluff with a fork and keep warm.
Meanwhile, in a skillet over high heat, brown the chicken in the oil. Season with salt and pepper. Add the pesto and chili pepper. Cook for 3 minutes or until the chicken starts to slightly caramelize. Deglaze with the broth and mix well.
Transfer the couscous to a serving dish and top with the chicken. Garnish with the cilantro and drizzle with the cooking liquid from the skillet.