Lock the lid onto the pot, make sure the release valve is turned to the 'sealed' position and press 'Pressure Cook'. The pressure should be set to normal and you will need to set the time to 50 minutes.
When the Instant Pot beeps that is is finished, move the release valve to quick release (watch your face and hands, there will be hot steam!).
When the pressure is fully released take the lid off the pot and carefully remove the pieces of beef. Place them into a separate bowl and shred the meat with two forks. Place some foil over it to keep it warm.
Take your hand blender and whizz up the onions and liquid left in the Instant Pot. If you like your gravy thicker you can switch your Instant Pot to 'Saute' and reduce it down further.
Now you are ready to assemble the sandwiches. Divide the the beef and cheese between the four rolls. You can put the rolls under a hot grill for a minute to melt the cheese if you want - just make sure not to burn the bread!
Spray a frying pan with low calorie cooking spray and set on a medium heat.Add the beef and brown on all sides.
Now you are ready to assemble the sandwiches. Divide the the beef and cheese between the four rolls. You can put the rolls under a hot grill for a minute to melt the cheese if you want - just make sure not to burn the bread!