01 - Boil green beans for 2 minutes, then drain and rinse under cold water. Pat dry thoroughly.
02 - Heat 1 tablespoon vegetable oil in a wok over high heat. Add green beans and stir-fry for 3 to 4 minutes until blistered and slightly charred. Remove and set aside.
03 - Add remaining 1 tablespoon vegetable oil to the wok. Fry Szechuan peppercorns for 30 seconds until fragrant, then add garlic, ginger, and scallions. Stir-fry for 1 minute.
04 - Add minced beef, breaking it up as it cooks. Stir-fry until browned and just cooked through, about 4 to 5 minutes.
05 - Stir in chili bean paste, soy sauce, oyster sauce, Shaoxing wine, sugar, white pepper, and optional chili flakes. Cook for 1 minute until fragrant.
06 - Return green beans to the wok, toss to combine, and stir-fry for 1 to 2 minutes until evenly coated and heated through.
07 - Drizzle with toasted sesame oil, toss well, and serve immediately.