Place fennel, peppers and onions in 9x13 casserole. Drizzle with 1 tablespoon evoo, salt, and pepper and toss together..
Coat chicken pieces with harissa and arrange in the pan among the vegetables. Place lemon slices on top of chicken and vegetables.
Roast chicken and vegetables for 40 minutes or until chicken is cooked through.
While chicken is roasting, prepare whole wheat couscous in a large deep serving platter, by covering with boiling broth and allowing to sit, covered, for 5 minutes. Fluff with fork and top with chicken and veggies.