When the Instant Pot beeps, allow the pressure to release naturally for 20 minutes, then carefully switch the steam release valve to Venting. When fully released, open the lid. Very carefully strain the hot broth from the pot through a fine-mesh sieve. Set the brisket aside and discard the ginger, onion, apple, and spices. Leftover bones and cartilaginous
bone caps from the oxtails can be saved and used again later to make bone broth. Season the strained broth with fish sauce to taste. Adjust the flavor by adding sweetener to taste, if desired.