Sprinkle salt on both sides of cube steak pieces.
Mix juice from canned tomatoes with Worcestershire Sauce, fish sauce, garlic powder and porcini powder, Pour about a ¼ cup in the bottom of Instant Pot Liner with the trivet removed. Put a layer of cube steak (overlapping is fine) in the Instant Pot liner and then a small handful of onions. Continue with this order until you get to the last layer of cube steak.
On top of the last layer of meat put any remaining onion, the bell peppers and tomatoes.
Pour remaining tomato juice mixture over the top.
On ‘Manual’ set the Instant Pot to 17 minutes. ‘Natural Release’ for 10 minutes
In the last 5 minutes of the ‘Natural Release’ mix the cornstarch and water in a small bowl (this is called a slurry).
After “Natural Release’ is finished, vent the remaining steam.
Remove lid. Remove cube steak pieces to a deep platter or casserole dish. Set Instant Pot to ‘Saute’ and add the black pepper. Pour in the cornstarch slurry and stir right away. After mixture has simmered for 1 minute, turn off heat
Pour the onion, pepper, and gravy mixture over cube steaks and serve!