Trim the fat from the roast and slice it in half if necessary. (Most roasts I find are 2+ pounds, and you it as even as possible for best results during cooking. Set the remaining roast aside for another batch of cheesesteak or other recipes.)

Add a pinch of salt and pepper to one side of the roast. 

Set the Instant Pot to its saute function and wait for the "hot" notification before spraying with a bit of nonstick cooking spray. Add the roast, salt and pepper side down, and set a timer for 3 minutes. 

After 3 minutes, flip the roast and set a timer for 2 minutes. 

After the 2 minutes, turn the Instant Pot off. Mix the soup mix, Worcestershire sauce, onion and pepper blend, and mushrooms to a large bowl before adding them to the Instant Pot. 

Seal the Instant Pot and cook on manual with quick release pressure for 4-5 minutes, depending on how well done you'd like your cheesesteak. 

After you've released the pressure, open the Instant Pot and remove the roast. 

Use a knife to chop the roast into small pieces or long strips depending on how you prefer your cheesesteak. Add the roast back in the Instant Pot to rest in the remaining juices for a few minutes. 

Serve as sandwiches, with fries or in baked potatoes, or lower carb/calorie options like cauliflower rice or a bed of roasted veggies.