Bring a large pot of water to a boil. Add the beef shank, tripe and tongue and blanch for 5 minutes, skimming off any foam and impurities that rise to the surface. Drain the meat and rinse it.
Place the star anise, cassia bark, Sichuan peppercorns, and the white cardamom, black cardamom and fennel (if using) into a spice bag or tea infuser. Return the meat to the pot and add 4 to 5 cups of water (enough to fully submerge everything). Add the spice bag, ginger, scallion, Shaoxing wine and salt.
Bring the mixture to a boil, then reduce the heat to a gentle simmer. Cover the pot and cook everything over medium-low heat for about 1½ hours, until the beef is cooked through but still firm enough to slice. Turn off the heat, remove the meat from the liquid with tongs or a spider, and reserve about ¼ cup (60 ml) braising liquid (you can discard the rest). Let the meat cool completely to room-temperature before assembling the dish; you can store it in the fridge to speed up the process.