Salt and pepper your chicken; grill your chicken until no longer pink. Brush with bbq sauce. Remove from pan and slice into very thin slices.
Toast and warm tortillas in griddle with the butter.
Grill pineapple after slicing.
Place tortillas on a baking sheet. Then layer cheese, chicken, pineapple, jalapeno and if desired, cilantro. I also added bacon, because seriously, bacon is great with everything. Ree also says you can drizzle extra bbq sauce on at this point. Top with another tortilla. Place in oven until cheese is melted.
Cut and serve with dipping sauce. I used sour cream to offset the heat. You could also do pico de gallo, guacamole, etc.