Turn your grill to medium-high heat and allow it to warm up to 375°F to 450°F.
While the grill is starting to heat up, season both sides of each piece of chicken with the seasonings listed above. Once the grill is all heated up, spray rack with cooking spray (lookout, it will shoot flames a bit)! Place each chicken on the grill, close the lid, and allow to cook for 4 to 5 minutes. No peeking!
After 4 to 5 minutes, open the grill lid and flip each piece of chicken. Close the lid again and cook another 4 to 5 minutes.
Once the chicken is done cooking, keep pieces on the grill and top with cheese until melted. Remove from grill then cover with foil to keep warm. Place pieces of pineapple on skewers. Place on medium-high heat grill. Allow cooking with grill cover open for 1 to 2 minutes on each side, or until charred. Assemble sandwich on bun and top with pineapple chunks.