sauté the onion and mushrooms in the bottom of the pressure cooker using the sauté mode and 2 Tbsp. olive oil until soft.
dissolve beef bullion cubes in 4 cups hot water
season both sides of the chuck roast with Montreal steak seasoning or whatever steak seasoning you like.
remove onions and sear both sides of the roast until they are golden brown
remove roast add stock and deglaze the bottom of the pan
return roast onions and mushrooms to the pot
pressure cook for 30 min. if it doesn't fall apart when pulling with 2 forks pressure cook for anther 10 minutes.
broil buns until they are lightly brown. remove before they are all the way toasted.
add beef cover with cheese and toast until cheese is bubbly.
pour broth into a small bowl for dipping
Enjoy!