What is a unique ingredient in the crispy Hawaiian chicken sandwich?

The unique ingredient in the crispy Hawaiian chicken sandwich is pineapple slaw. This ingredient adds a distinctive tropical twist that complements the other flavors in the sandwich. Pineapple slaw typically combines fresh pineapple with shredded cabbage and a tangy dressing, which enhances the overall taste experience by adding sweetness and crunch.

While spicy aioli, bacon, and provolone cheese may all contribute to the flavor profile of many sandwiches, they are more commonly used in various dishes and do not provide the same recognizable Hawaiian flair as pineapple slaw does. This particular slaw not only enhances the regional theme of the sandwich but also sets it apart, making it the standout ingredient.