Heat oil, chili powder, peppercorns, and cinnamon in a wok over low heat for 10 minutes. Transfer to a bowl, then whisk in soy sauce, vinegar, wheat paste, and sesame paste.
Combine pork, Shaoxing wine, and soy sauce. Cook pork in a wok until browned. Add garlic and ginger. Cook bok choy, then noodles.
Divide noodles into bowls, top with pork mixture and bok choy. Garnish with scallions and serve.
