Heat the stock in a stock pot with the ginger and reduce by 20 percent. Add the bok choy, white pepper, and soy sauce. Cook for 3 minutes until bok choy is soft. Check for seasoning. Place the hot noodles in 4 large bowls and top with stock and bok choy. Place sliced beef on top. Garnish with scallions, cilantro, and drizzle with sesame oil.
Five Spice Beef Shank:
Prepare a large non-stick stock-pot coated with oil over high heat. Add the crushed pepper, ginger, and garlic and stir for 30 seconds. Place the beef in the stock-pot and cook, covered about 4 minutes on each side. Add the soy sauce, red wine, five spice powder, salt, star anise, cinnamon, and rock candy and bring the mixture to a boil for about 5 minutes.
Reduce the heat and let simmer for 2 1/2 hours turning the shank every 20 minutes. Remove the shank from the pot and let cool before slicing and adding to the Wonton Noodle Soup.