01 - In a medium bowl, whisk together the soy sauce, pineapple juice, brown sugar, olive oil, garlic, ginger, and black pepper until well combined.
02 - Place chicken breasts in a large resealable bag or shallow dish. Pour the marinade over the chicken, ensuring each piece is evenly coated. Refrigerate for at least 30 minutes, or up to 4 hours for deeper flavor penetration.
03 - Preheat grill to medium-high heat (approximately 400°F). Lightly oil the grates to prevent sticking.
04 - Remove chicken from the marinade, allowing excess to drip off. Grill for 5 to 7 minutes per side until the internal temperature reaches 165°F. Discard remaining marinade.
05 - While the chicken cooks, grill the pineapple rings for 2 to 3 minutes per side until lightly charred and caramelized.
06 - Arrange the grilled chicken on a platter, top with charred pineapple rings, and garnish with sliced green onions and sesame seeds if desired.