Pour 1/4 cup Wish-Bone® Italian Dressing over chicken in large resealable plastic bag; turn to coat. Repeat with mushrooms in additional 1/4 cup dressing in separate resealable bag. Close bags and marinate in refrigerator up to 3 hours.
Remove chicken and mushrooms from marinades, discarding marinades. Grill or broil chicken and mushrooms, turning once, until chicken is thoroughly cooked and mushrooms are tender. Thinly slice chicken and cut mushrooms in half.
Arrange spinach on serving platter. Top with apple, dried cranberries and cheese, then mushrooms and chicken. Drizzle with remaining 1/4 cup Dressing just before serving.