Season each side of the chicken with salt and ground black pepper. Grill on medium heat until the chicken is cooked through, turning over halfway through.
While the chicken is cooking, grill the pineapple slices on each side, just long enough for grill marks to appear.
During the last few minutes of grilling, baste the chicken on each side with barbecue sauce. Grill for an additional 1 minute per side.
Build each sandwich by placing a layer of lettuce and then two slices of bacon in a cross pattern on the bottom half of bun.
Layer the chicken and mozzarella cheese on top of the bacon.
Top with the pineapple.
Place the top half of the bun on the sandwich.
Eat and enjoy!
Recipe by Slyh in the Kitchen at https://www.slyhkitchen.com/2015/04/22/bbq-chicken-pineapple-sandwich/