In a small frying pan over medium-low heat, toast the cinnamon, star anise, cloves, coriander, fennel, cumin, and peppercorns, for about 3-5 minutes until fragrant. Place the cloves, coriander, cumin, and fennel in a muslin cloth and tie the cloth with kitchen twine to make a little sachet.
Program an 8-quart programmable IP to Sauté. Add 1 tablespoon of oil making sure to coat the bottom. Sear the beef shank in two batches until all sides are brown, about 5 minutes, adding another tablespoon of oil between batches as needed. Transfer seared beef to a plate.
In the same pot, heat the remaining oil. Add the ginger, garlic, onion, and dried chilies and cook until fragrant, about
Add sugar and tomatoes and continue to cook until tomatoes have softened, about
Add toban djan, Shaoxing wine, soy sauce, and water. Mix everything up with a ladle.
Add cinnamon, star anise, and spice sachet.
Return beef shank and beef tendon to the pot.
Press Cancel button to reset cooking program. Lock lid. Select Pressure Cook at high pressure for 45 minutes. Naturally release the pressure for 15 minutes then manually release pressure from cooker until float valve drops.
Unlock lid. Remove beef and tendon and transfer them to a container big enough to hold them. Beef and tendon should be chewy-tender but still have some bite.
Strain the soup through a colander into a clean pot, and discard the solids.
When the beef pieces have cooled, cut them into smaller pieces. Add meat and tendon back to strained broth.
Bring the broth back to a slight boil, add bok choy, and simmer just until tender. Remove them from the broth. Season the soup with black vinegar, and additional soy sauce and sugar to taste.
Cook the noodles in a large pot of boiling water according to the package directions, and drain them.
Divide the noodles among large soup bowls, top with bok choy, mustard greens, and pour the soup over them. Garnish with scallion and cilantro. Serve immediately.