Cut the onion into strips and the tomatoes into wedges. Add to the Instant Pot with the oil and condiments. Press Saute and set time to 6 Minutes at high temperature. Stir continuously.
Once the time is up, add the beans (presoaked and rinsed) with the water.
Close and lock the Instant Pot® lid. Make sure the steam release handle is turned to Sealing. Press Pressure Cook and set time to 15 Minutes.
Then release the pressure naturally for 10 Minutes.
Once all the pressure has been released, add the corn and tomato sauce. Return to the Saute setting for 5 Minutes at high temperature to cook the corn and give the mixture more consistency.
And done! You can eat it as is or leave in the refrigerator to thicken even more.