It takes about 1 hour per pound of meat to cook a pot roast at 275 degrees Fahrenheit. For example, a 3-lb. cut of beef will take 3 hours to cook fully at this temperature. The best cuts of meat to use are tough cuts, such as chuck, which will slowly tenderize at the low temperature, notes The Kitchn.
A typical recipe for pot roast can include salt, black pepper, olive oil, carrots and onions. These ingredients are combined into a Dutch oven with the beef and quickly browned, then roasted for the required number of hours. A cut of beef with a large amount of marbling will result in a pot roast with a lot of flavor.