Set oven control to broil. Line broiler pan without rack with foil; spray foil with cooking spray. Place chicken in pan. Brush tops of chicken with preserves.
Broil 4 to 6 inches from heat 10 to 12 minutes, turning once and brushing frequently with remaining preserves, until juice of chicken is clear when center of thickest part is cut (170°F).
Meanwhile, cook couscous in water as directed on box omitting oil.
Spoon couscous onto serving platter; arrange chicken over couscous. If desired, garnish with grated orange peel.