Creating Hawaiian Chicken Sandwiches is a simple process if you follow these steps:

1. Prepare Marinade: In a bowl, mix pineapple juice, soy sauce, brown sugar, minced garlic, minced ginger, and black pepper.
2. Marinate Chicken: Place chicken breasts in a resealable bag and pour the marinade over them. Seal and refrigerate for at least 30 minutes.
3. Preheat Grill: Heat your grill or grill pan to medium-high.
4. Grill Chicken: Remove chicken from the marinade and grill for about 6-7 minutes on each side, or until fully cooked.
5. Grill Pineapple: If using, place pineapple slices on the grill for about 2-3 minutes per side until grill marks appear.
6. Prepare Buns: Slice the hamburger buns in half and toast them lightly on the grill or in a toaster.
7. Assemble Sandwiches: Spread mayonnaise on the bottom half of each bun. Place a grilled chicken breast on top, followed by grilled pineapple, lettuce, tomatoes, and red onion.
8. Add Sriracha: Drizzle sriracha sauce on top if you prefer a spicy kick.
9. Top and Serve: Place the top half of the bun on each sandwich and serve immediately.

Following these steps will guide you in creating Hawaiian Chicken Sandwiches that are bursting with flavor!