If cooking on an outdoor grill, the grilling can all be done at once, starting with the green beans, and then adding the onion after about 8 minutes and the chicken after 12. If cooking on a double-burner grill pan, grill the vegetables first and once they are done, grill the chicken all at once. For an even quicker meal, you can purchase 8 chicken cutlets (about 2 pounds), instead of boneless skinless chicken breasts.