Preheat oven to 425º
Cut chicken into roughly 1 inch chunks, and place on sheet pan
Dice onion, bell peppers, and mince garlic, and also add to sheet pan
Drizzle with olive oil, and toss to evenly coat with oil. You can use two spoons, or your hands
Spread chicken and vegetables evenly in a single layer over sheet pan
Sprinkle with salt and pepper
Roast in center of oven for about 15 minutes, until the chicken is cooked through
While chicken is roasting, pour pineapple juice from the canned pineapple into a sauce pan
Add cornstarch, and stir until lumps dissolve
Add remaining sauce ingredients, including pineapple chunks, and cook over medium heat, stirring until sauce thickens
When chicken is done, remove from oven and toss with sauce
Serve over warm rice
Note: I use light olive oil because it has a higher smoke pointWhite vinegar can be substituted if you don’t have rice vinegar