This recipe is linked from the Holiday Cheat Sheet on "Roasts" as a way to use leftover roast. How would you adapt this recipe if the meat was alr...

Depends on what type of roast you have and how well done it is. Since the recipe uses a well marbled chuck roast one expects the meat to be tender and shreadable after cooking that long in the liquid. If you have a rarer firmer meat, you would likely cook it as long as the recipe suggests. If you have more well done meat you may be able to cut back the time significantly so that the flavors come together and flavor the meat but you would not be needing to cook it that long.