In a large bowl, combine cumin, lemon and orange rinds, and 2 Tbsp (30 mL) olive oil. Add chicken, turning to coat. Cover and refrigerate for two to three hours.
Meanwhile, place lentils in a medium saucepan and cover with 3 cups (750 mL) water; bring to a boil, lower heat and simmer 30 minutes or until soft.
Drain lentils, then place in a medium bowl with lemon and orange juices and the remaining 2 Tbsp olive oil. When cool, mix in carrots and cilantro. Season to taste.
Heat grill to medium and cook chicken on one side for five minutes. Turn over, reduce heat to low, and cook for nine minutes more. Remove, cover with foil and allow to rest for three minutes. Check if chicken is cooked through. Place a chicken breast on each of four plates and serve with the lentil salad.
Per serving: 425 calories, 48 g protein, 11 g fat (2 g saturated fat), 34 g carbohydrates, 16 g fibre, 87 mg cholesterol, 148 mg sodium