1. Add olive oil to an Instant Pot and set it to Saute.
2. Salt and pepper chuck roast. Add chuck roast to the Instant Pot and brown the meat on both sides, 3-4 minutes per side.
3. Add beef broth, Worcestershire Sauce, mushrooms, bay leaves and garlic to the Instant Pot.
4. Pressure cook on High (or on Beef/ Stew setting) for 65 minutes. If your roast is bigger, then add 10 minutes cook time for each extra pound. Once the cook time is over, allow the steam to release naturally for 10 minutes, then vent the remaining steam with the release valve.
5. Remove roast and place it on a cutting board. Remove mushrooms and set aside.
6. Remove bay leaves and garlic cloves and throw away.
7. Once the roast is cool enough to handle, pull the meat apart with 2 forks. Scrape the larger pieces of fat off as you pull the meat.
8. Return the meat and mushrooms to the Instant Pot and allow to rest in the cooking liquid for 10 minutes before serving.