Rinse pork belly and pat dry. Turn on the Instant Pot to Saute and add 1 teaspoon oil. Place pork belly in to brown on all sides for about 3-4 minutes.
Add the chilies, garlic, spices and ginger and saute until fragrant. Add soy sauce, sugar, and 4 C of beef broth or water to cover. Cover with the lid and set the Instant Pot to Meat setting and cook for 40 minutes at high pressure.
Once pork belly is cooked, remove from braising liquid and cut into pieces that fit into baos. Strain the braising liquid and remove the fat from the surface.
Pour some of the braising liquid into a sauce pan and bring to a low boil. Throw in a little cornstarch slurry and stir until thick before tossing the cut pork slices in mixture.
Place pork into steamed buns and add the trimmings!