Preheat the grill to medium-high heat.

In a mixing bowl, combine the chicken breasts, pineapple chunks, teriyaki sauce, bell pepper, zucchini, olive oil, garlic powder, ground ginger, and black pepper.

Toss everything together until the chicken and vegetables are well coated in the sauce.

Cut four large pieces of aluminum foil and place an equal amount of the chicken and vegetable mixture in the center of each piece.

Fold the foil over the mixture to create sealed packets.

Place the foil packets on the grill and cook for 15-20 minutes, or until the chicken is cooked through and reaches an internal temperature of 165?F.

Carefully open the packets, sprinkle with sesame seeds, and serve hot.