In large bowl, marinate chicken tenderloins in ½ cup of Marie’s Balsamic Vinaigrette Dressing for 30 minutes. Sprinkle chicken with salt and pepper. Discard marinade. Broil marinated chicken on foil-lined broiler pan for 8 minutes, turning once.
Cut focaccia bread in half horizontally. Place bread on baking sheet with cut sides up and brush with additional Marie’s Balsamic Vinaigrette. Broil bread for 3 minutes until toasted. Arrange the broiled chicken tenderloins over bottom half of bread. Layer with spinach leaves, basil and sliced mozzarella cheese on top. Place under broiler again for 2 minutes or until cheese melts. Cover with top half of bread. Cut into equal pieces to serve.