Place the roasted bones, onion, carrot, celery, ginger, salt and pepper in a large pot. Add enough water to cover, approximately 6 cups.
Bring the pot to boil on high heat. Turn the heat down to a low simmer. Let simmer for 1-2 hours. The longer it simmers, the tastier the broth will be.
In the last 15 minutes before the broth is done, prepare the noodles and the pork.
Bring a large pot of water to boil to make the noodles.
Meanwhile, in a large frying pan or wok on medium high heat, add cooking oil. Add ginger and garlic and cook for 30 seconds, until fragrant.
Push the aromatics aside and add ground pork, flattening it out to form a patty. Let it sear for 1 minute and flip over. Sear for another minute before breaking it up and combining the aromatics. Cook for about 3-5 minutes, until the pork is no longer pink and cooked through.
Stir in the light soy sauce, dark soy sauce, rice wine, oyster sauce and sugar.
Once the noodles are cooked, divide them into individual bowls.
Blanch the napa cabbage in the same water that the noodles were cooked in for 1 minute. Divide the cabbage on top of the noodles.
Add a portion of the cooked pork to the top of the noodles.
Ladle the broth over the noodles.
Drizzle with sesame oil, season with ground white pepper and garnish green onion.