Stir together cornstarch, soy sauce, cooking wine, cayenne powder and 1/8 tablespoon salt in a bowl. Add chicken and toss. Let stand at room temperature for at least 1 to 2 hours or refrigerate up to overnight.
Preheat oil in a deep-fryer to 350 degrees F.
Soak wedges of russet potato in cold water for at least 15 minutes, then drain. Dry well, then deep-fry until pale golden. Set aside.
Deep-fry string beans until slightly softened and top layer of skin is slightly blistered. Set aside.
Deep-fry marinated chicken until golden brown. Set aside.
Heat vegetable oil in a wok over high heat and add ginger, garlic, green onion, dried chile peppers and Sichuan peppercorns to infuse with the oil. Turn heat to medium-high and stir back and forth for about 15 seconds.
Add the chicken, potatoes and string beans, flipping the wok a few times after each addition. Once the infused oil and aromatic ingredients are well incorporated with the chicken, potatoes and beans, sprinkle with black and white pepper and the remaining 1/8 tablespoon salt. Transfer to a platter and serve.
This recipe was provided by a chef, restaurant or culinary professional. It has not been tested for home use.
Recipe courtesy of Peaceful Restaurant, Vancouver, Canada