Dice the chicken into even-sized pieces. Peal and/or seed the bell peppers, onion, celery, and carrot, then dice into pieces the same size as the chicken. Break the broccoli into small florets the same size. Finely mince the garlic.
Heat the peanut and sesame oils in a pot to medium heat. Swirl the oils to cover the base of the pot then add the diced chicken. Cook, regularly stirring, until the chicken is lightly browned on all sides, about 6 minutes.
Add the diced bell peppers, onions, celery, carrot, broccoli, and garlic. Cook while regularly string until the onions are translucent, about 6 minutes.
Add the water and bring it to a simmer.
Sweet and Sour Sauce
Open the can of pineapple and drain the juice into a bowl, then add the pineapple chunks to the simmering chicken and vegetables.
Add the Shaoxing rice wine, soy sauce, ketchup, and corn starch to the pineapple juice. Whisk with a fork until well combined. Slowly pour into the simmering chicken and vegetable stew, while continuing to stir, until boiling and the sauce thickens.
Cook or reheat the rice according to package directions. Serve the chicken stew over the cooked rice.