POUR dressing over chicken in shallow non-reactive pan. Refrigerate up to 2 hours.
REMOVE chicken from marinade; discard marinade. Grill chicken on medium-high heat 2 to 3 min. on each side or until done (165ºF). Keep warm.
FOR each serving: Spread each of 2 toast slices with 1 Tbsp. mayo. Fill with 1 chicken breast, 2 Tbsp. salad greens, 1 pepper half and 1 cheese slice.