Pat dry the pork with paper towels and sprinkle salt and pepper on both sides.
Add the sesame oil into the inner pot and turn on the SAUTE function. Once hot, add the pork and brown the edges, flipping it over to brown all sides.
Transfer the browned pork to a plate and immediately add the 240ml water to the inner pot. Turn off saute and scrape off any brown bits stuck to the bottom with a wooden spoon.
Add the remaining ingredients, except for the thickener into the inner pot and stir to mix well.
Transfer the cooked pork back into the Instant Pot and put on the lid.
Select PRESSURE COOK on high for 1 hour.
Once the program has finished, perform a quick pressure release, and remove the pork from the pot into a serving dish and use two forks to shred the pork.
Select the SAUTE function again and bring the sauce to a boil. Whisk the corn flour and water together in a small bowl and add this to the pot, to thicken the sauce. Stir well. (If the sauce is still thin, you can make some more thickener and add a little more to your desired sauce thickness.
Once ready, turn off the saute function and transfer the sauce on top of the shredded pork.
Serve in bao buns (recipe can also be found in this cookbook) or with rice.