In a large resealable plastic bag, place chicken breasts. Pour mesquite-lime marinade over all. Seal and turn to coat. Place in refrigerator for 1-4 hours.
In a large skillet over medium heat, heat the olive oil, then add onion and bell peppers. Sauté 5-6 minutes. Remove from heat and set aside.
Preheat grill to medium-high heat.
Grill chicken breasts 10-15 minutes on each side, or until meat is cooked through and no longer pink in the middle. Remove from heat, cool slightly and then slice into strips.
In a large salad bowl, toss together the lettuce, tomato, onion, red and yellow pepper, cheese, croutons, salad dressing and chicken until evenly coated. Serve. Garlic breadsticks would be a nice side to serve with the salad.
