squeeze 2 of the lime quarters over chicken, then place chicken on grill rack. grill 12 to 15 minutes or until chicken is no longer pink (165°f), turning once. transfer to a serving platter; squeeze remaining lime quarters over chicken. cover with foil and let stand 5 minutes.
meanwhile, for sauce, in a small saucepan stir together milk and soup over medium heat just until heated through. spoon sauce over chicken, and sprinkle with cheese. serve immediately. 