Creating Grilled Hawaiian Chicken Sandwiches is a straightforward process. Follow these easy steps:

1. Marinate Chicken: In a bowl, combine chicken breasts with barbecue sauce, ensuring they are well-coated. Let them marinate for at least 30 minutes in the refrigerator.
2. Preheat Grill: Preheat your grill to medium-high heat. If using a grill pan, place it over medium heat on the stove.
3. Prepare Pineapple: If using fresh pineapple, slice it into rings. Lightly brush them with olive oil.
4. Grill Chicken: Remove the marinated chicken from the refrigerator. Place the chicken on the grill and cook for 6-7 minutes on each side, or until fully cooked (internal temperature should reach 165°F).
5. Add Pineapple: During the last few minutes of cooking, add the pineapple rings to the grill. Grill until they are caramelized and warm, about 2-3 minutes.
6. Melt Cheese: In the final minute of cooking, place a slice of cheddar cheese on each chicken breast to melt.
7. Toast Buns: Lightly toast the hamburger buns on the grill or in a toaster for added texture.
8. Assemble Sandwiches: On the bottom half of each bun, place a lettuce leaf, followed by a grilled chicken breast topped with a pineapple ring. Finish with any additional toppings you prefer, then secure with the top half of the bun.
9. Serve Immediately: Enjoy your delicious sandwiches while hot!