Chuck roast is a fatty cut of beef so in order to remove as much of that fat from the cooking liquid as possible, I like to cook this a day in advance. After the initial cooking time and before shredding the beef, I allow it to cool and then refrigerate it overnight in the slow cooker insert. The next morning the fat will have collected on the surface of the liquid and be very easy to remove. Then I return the insert to the slow cooker and when the beef is warm, I shred it and continue with the recipe as written.