Preheat oven to 400℉. Line a large sheet pan with foil.
In a large bowl, add the chicken, peppers, and onions.
In a small bowl, stir all of the sauce ingredients together. Set aside half of the sauce (about 1/3 cup) in a microwave safe bowl and pour the remaining sauce on top of chicken mixture. Stir to coat. If not making right away this can marinate up to 24 hours in the fridge.
Spread chicken mixture evenly on the sheet pan. Sprinkle with salt and pepper. Bake for 20 minutes. Remove from the oven and add the pineapple. Return for 5-10 minutes or until chicken is done and reaches 165 ℉.
While chicken is cooking, heat reserved sauce in the microwave for about 45-60 seconds or until thick. When chicken is done drizzle sauce on top of the chicken and veggies. Garnish with cilantro or parsley if desired. Serve plain or over cooked rice.