Heat the vegetable oil in a large pot over medium heat. Add the garlic and ginger, and sauté until fragrant.
Add the beef shank or brisket and brown on all sides.
Add soy sauce, dark soy sauce, rice wine, and sugar, and stir to coat the beef.
Pour in the beef broth and add the star anise and five-spice powder. Bring to a boil, then reduce the heat and simmer for 2-3 hours, until the beef is tender.
Strain the broth, return the liquid to the pot, and simmer for another 30 minutes to allow the flavors to meld together.
Cook the noodles according to package instructions and divide them into bowls.
Pour the broth over the noodles and top with the tender beef. Garnish with chopped green onions, cilantro, and pickled mustard greens if desired.