Marinate the chicken: In a large bowl, combine the chicken with soy sauce, dry sherry, and arrowroot powder. Toss thoroughly to coat and allow it to marinate while preparing the sauce.

Prepare the kung pao sauce: In a small mixing bowl, whisk together tamari soy sauce, water, dry sherry, rice vinegar, honey, sesame oil, and arrowroot powder until smooth. Set aside.

Toast the nuts: Heat a large wok or sauté pan over medium-high heat. Add the cashews or peanuts and dry roast for approximately one minute, stirring continuously until lightly golden. Transfer to a separate bowl.

Cook the chicken: Add 2 tablespoons of oil to the heated pan. Stir-fry the chicken for 3–4 minutes until it is cooked through and lightly browned. Remove from the pan and set aside.

Sauté the vegetables and aromatics: If needed, add the remaining oil to the pan. Stir-fry the bell pepper, dried chilies, garlic, ginger, and Sichuan peppercorn powder for 3–4 minutes, allowing the flavors to release.

Combine and finish: Re-stir the kung pao sauce to ensure any settled arrowroot is incorporated, then pour it into the pan. Add the chicken and sliced green onions, stirring for 1–2 minutes until the sauce thickens and becomes glossy. Turn off the heat, fold in the roasted nuts, and mix to combine evenly.