Rinse the buckwheat by putting in a sieve, and rinse it under running water.
Add water and buckwheat to the pressure cooker. Add salt, and oil. Close lid start the pressure cooker in MANUAL or pressure cook mode at high pressure for 5 minutes.
When the pressure cooker beeps, do 10 minutes natural pressure release, which means release the pressure and open the lid 10 minutes after it beeps.
Fluff with a fork. Then take the steel insert out of the instant pot, so that the bottom layer does not overcook.