For the chicken: Sprinkle the chicken with the salt and white pepper in a large bowl. Add the cornstarch and mix well.
For the sweet sauce: Stir together the bean paste, light soy, chili sauce, tomato paste, vinegar, brown sugar and dark soy in a large bowl until combined and set aside.
For the stir-fry: Heat a wok over high heat until it starts to smoke. Pour in the peanut oil, and then stir-fry the chiles and garlic for a few seconds. Toss in the onions and stir-fry, about 1 minute. Then add the chicken and stir-fry for about 2 minutes. As the chicken starts to turn opaque, add the peanuts, if using, and rice wine. Cook for another 3 minutes, and then pour in the sweet sauce.
Add the red pepper and cook the chicken in the sauce until cooked through and the sauce has reduced and become slightly sticky with a thicker consistency, about 2 minutes. Add the scallions and cook, tossing, about 30 seconds. Transfer the chicken to a serving platter.
Serve immediately with rice sprinkled with sesame seeds and chili powder.