Preheat your oven to 400°F (200°C).

In a mixing bowl, combine pineapple, bell peppers, and red onion. Drizzle with olive oil, garlic powder, salt, and pepper, and toss to coat.

Spread the chicken breasts and vegetable mixture on a baking sheet in a single layer.

In a separate bowl, mix teriyaki sauce, soy sauce, honey, and rice vinegar. Drizzle over the chicken and vegetables.

Roast in the oven for 25-30 minutes until chicken is cooked through (165°F or 74°C) and vegetables are tender.

Let rest for a few minutes, then garnish with sesame seeds and green onions before serving.

Serve over cooked rice if desired.