Add the chicken to a medium bowl along with the water, cornstarch, neutral oil, soy sauce (or oyster sauce). Mix until the chicken is coated. Set aside and marinate for about 20 minutes while you prepare the other ingredients.
Make your sauce by combining the pineapple juice, chicken stock, sugar, soy sauce, mirin (or Shaoxing wine), chili garlic sauce, and white pepper.
Heat your wok until it’s just starting to smoke. Add 1½ tablespoons of oil to coat your wok completely. Add the chicken evenly in one layer. Sear on one side for 30-60 seconds. Flip the chicken; it should be nicely browned. Sear for another 30-60 seconds. Use your wok spatula to stir-fry the chicken, moving it around the wok until there are no visible raw spots. Reduce the heat to low, and transfer the chicken to the same marinating bowl. (It will cook again. It should be 80% done at this point.)
Increase the heat slightly to medium-low. Add the remaining ½ tablespoon of oil and add the ginger. Stir and let the ginger infuse the oil for 10-15 seconds. Add the garlic and bell peppers. Give everything a stir, and increase the heat to high.
Add the pineapple chunks and continue to stir-fry for another 30 seconds, giving them a light sear. Stir in the seared chicken and its juices. Add the premixed sauce and give everything a stir-fry to deglaze the wok. Once the mixture comes to a boil, stir in the cornstarch slurry mixture. Continue stir-frying the chicken until the sauce thickens and reduces. Serve with steamed rice!