Whip Up the Marinade: In a medium bowl, whisk together the soy sauce, pineapple juice, brown sugar (or honey), ketchup, rice vinegar, minced garlic, and grated ginger. This is your flavorful Hawaiian marinade! Set aside a quarter cup of this mixture for a delicious drizzle later.
Marinate the Chicken: Add your chopped chicken pieces to the main marinade bowl. Toss gently to coat every piece evenly. Let it marinate for at least 30 minutes while you prep your veggies, or pop it in the fridge for up to 24 hours for deeper flavor infusion.
Preheat & Prep Your Pan: Get your oven nice and hot by preheating it to 425°F (220°C). Line a large sheet pan with parchment paper for super easy cleanup – a healthy cook's best friend!
Toss the Veggies & Fruit: On the prepared sheet pan, combine the chopped bell peppers, red onion wedges, and pineapple chunks. Drizzle them with olive oil, a sprinkle of sea salt, and black pepper. Give them a good toss until everything is lightly coated.
Add the Chicken & Roast: Evenly spread the marinated chicken pieces among the colorful veggies and pineapple on the sheet pan, making sure it's all in a single layer so everything roasts instead of steams.
Bake to Perfection: Slide the sheet pan into the preheated oven and bake for 25 to 30 minutes. Halfway through, flip the chicken and veggies for even cooking and golden caramelization. Your chicken is perfectly cooked when it's no longer pink inside. For an extra burst of freshness, you can add a few more fresh pineapple chunks during the last 5 minutes of baking.
Thicken Your Drizzle (Optional): While your dinner is baking, gently simmer the ¼ cup of reserved marinade in a small saucepan over medium heat. If you want a thicker sauce, mix the cornstarch with water to create a slurry, then stir it into the simmering marinade. Cook for about a minute, stirring constantly, until it thickens into a lovely glaze.
Serve & Enjoy: Once baked, drizzle the delicious thickened sauce over your tropical Hawaiian chicken and veggies. Serve this wholesome meal hot over fluffy steamed rice, coconut rice, or even cauliflower rice for a low-carb option. Garnish with fresh chopped parsley or green onions and maybe a squeeze of lime for extra zing!