Preheat your oven to 400°F (200°C) and lightly grease a large baking sheet.
Place the chicken pieces, pineapple chunks, red and green bell peppers, and red onion on the baking sheet. Drizzle with olive oil and toss to coat.
In a small bowl, whisk together the soy sauce, pineapple juice, brown sugar, garlic, ginger, and cornstarch.
Roast the chicken and vegetables in the oven for 15 minutes.
Remove from the oven, pour the prepared glaze over the mixture, and toss to coat evenly.
Return the pan to the oven and roast for an additional 10 minutes, or until the chicken is cooked through and the sauce is thick and sticky.
Serve warm over cooked white rice and garnish with sliced green onions.