Season the steak with the salt and pepper on both sides.
Heat the Instant Pot on sauté mode, add the cooking oil. When hot, place the steak in the pot and sear for 1 minute per side.
Turn off sauté mode. Remove the steak. Pour in the hot beef broth and deglaze the pot with a whisk to remove the browned bits.
Add the steak back into the pot.
Secure the lid in place and set the valve to sealing. Press the pressure cook or manual button and set the time to 4 minutes. It will take about 5 minutes to come up to pressure.
When the time is up, do a quick pressure release and transfer the steak to a plate to rest for 5 minutes.
Slice the steak and serve.
Notes
I cooked this in the 6 quart Instant Pot. If you cook in an 8 quart pot, use 1 1/2 cups water. If you cook in a 3 quart pot, you might need to cut the steak in half to fit. Use the same amount of water.
The meat will be medium to well-done in 4 minutes. If you want to cook it to well done, add 2-3 more minutes to the cook time. It’s difficult to get medium-rare in the Instant Pot because the steak is cooking in water, but you can try 3 minutes for medium-rare.
Add an extra layer of flavor with a meat marinade or homemade dry rub.
Let the steak rest for a few minutes before slicing it. This will give you a juicier cut of flank steak.