Taiwanese Beef Soup

Fill a large pot or Instant Pot with water and bring to a rapid boil. Add beef shanks and boil vigorously for about 3 minutes to get rid of the impurities. Drain, rinse and cut the beef shank into thick slices. Set aside.
Select the "saute" setting. Heat the oil, then add onion, scallions, ginger, garlic, bay leaves, red chilies, star anises, Dou Ban Jiang until fragrant and the onion is translucent. Add tomatoes, dark soy sauce, light soy sauce, and Shaoxing wine. Stir for about 8 minutes then add beef shanks into the pot.
Instant Pot users: Cook for 90 minutes at high pressure and do a quick release.
Stove-top users: Add more water if needed so the meat is covered. Bring to a boil over medium-high heat. Reduce the heat then cover the pot, cook slowly at low heat for 2-3 hours or until the meat is tender. Add more liquid if necessary.
Remove the bay leaves and other spices from the broth. Serve with noodles, and toppings of your choice.