Make sure the green beans are dry, with no water clinging to them. Heat 1 inch of oil in a wok over high heat until little bubbles appear around a bean dropped in the oil.
Add the green beans and fry for 8 to 10 minutes, stirring occasionally. The bean skins should look crinkly with brown spots. Using a perforated strainer, transfer the beans to paper towels to drain.
Drain all but 1 tablespoon of oil from the wok and reheat over medium-high heat. Add the Sichuan peppercorns and stir-fry for 10 seconds. Drop in the garlic, ginger, chiles, and green onions and stir-fry for 20 seconds (be careful not to burn the spices).
Add the pork and stir-fry for 1 minute, or until all the meat is browned. Toss in the green beans, soy sauce, and chicken powder and stir-fry for 1 more minute. Season with salt to taste and serve.?.