Although moist and tender when first served, roast does not always yield the same result when reheated. Reheating a roast often results in dry, tough meat that seems more like jerky in consistency. However, before resigning yourself to eating an entire roast in one sitting or throwing away any uneaten meat, it is possible to revive leftover roast. When it comes to reheating roast, the key is to use a method that retains the meat's moisture.
Skim and discard the fat from the sauce. Heat the gravy or sauce in a saucepan over medium-high heat for 10 to 15 minutes or until it is no longer congealed and thoroughly warm.
Preheat the oven to 350F. Carve the roast into thin, serving size slices. Place the carved slices in a casserole dish.
Pour the heated gravy over the slices of beef. Cover the casserole dish with foil and place the dish in the oven. Heat the roast for 25 minutes.
Skim and discard the fat from the sauce. Pour the sauce in the saucepan and heat over medium-high heat until boiling.
Carve the roast into thin slices. Drop two to three slices into the sauce; fewer if the pot is small. Do not overcrowd the pot.
Leave the slices in the sauce for 5 to 10 minutes or until thoroughly warm. Remove the slices and serve immediately.