When cooking a pot roast, using the correct temperature and time is crucial if you want to end up with a moist, tender roast. Cooking the roast for too long or cooking it at too high of a temperature can cause the pot roast to come out dry, tough and chewy. If this happens, there are a few ways to salvage the beef, although it will take extra time -- up to six hours. Infusing the tough beef with moisture and slow cooking it will fix the problem and soften the roast a little bit.
Shred the roast by pulling it apart with two forks. Place all the shredded roast meat into a large saucepan.
Cover the beef with the moisture provider of your choice. Depending on which flavour you'd like the beef to have, you can use beef broth and sliced onions, canned tomatoes, barbecue sauce, or water and a packet or two of onion soup mix. Make sure that the liquid covers the beef by 1.2 cm (1/2 inch).
Bring the liquid to a boil, and immediately lower the temperature so that the beef is simmering. Cover the pot, and allow the beef to simmer for as long as possible, for two to six hours.
The simmered beef can be used on sandwiches, in tacos, over pasta or rice, or in burritos.