Heat a teaspoon of oil in a wok over medium heat and add a cup of raw shelled peanuts.
Stir constantly for three minutes, then turn off the heat and continue stirring for another minute using residual heat.
Set aside to cool completely, allowing them to turn crunchy.
Alternatively, use already roasted shelled peanuts.
Mix the chicken with all the marinade ingredients in a bowl and let it sit for 20 minutes.
In a separate bowl, combine all the sauce ingredients and set aside.
Heat two tablespoons of oil in a wok over high heat, sear the chicken, then remove it to a bowl.
Lower the heat, add another tablespoon of oil, and sauté garlic, ginger, chilies, Sichuan peppercorn powder, and scallions for a minute or two until fragrant.
Return the chicken to the pan, increase the heat to high, and stir-fry for a minute.
Stir up the sauce to incorporate the settled cornstarch, then add it to the wok.
Stir-fry for another minute until the sauce thickens.
Finish by adding the peanuts, giving everything a final stir, and serving hot.