Although reheating steak to 165 degrees Fahrenheit prevents foodborne illnesses, how you bring it to 165 F affects the quality. You want the steak to reach 165 F while retaining as much moisture as possible and without changing the texture of the meat, which makes the oven your best choice. You also have to prepare different types of steak differently for reheating. For example, sliced steak reheats best in a small foil packet, whereas a large steak or roast does best when reheated in hot beef stock in a covered dish. You should never reheat steak more than once.
Place the steak on a plate and let it reach room temperature. Heat the oven to 350 F.
Place a roasting rack in a baking pan and place the steak on it. Bring a saucepan of water to a boil.
Pour enough hot water in the pan to reach just under the steak. Cover the pan with an ovenproof lid or aluminum foil and place it in the oven.
Warm the steak for seven minutes, then check for an internal temperature of 165 F with an instant-read thermometer.
Place the leftover steak on a plate and let it reach room temperature. Set the oven to Warm.
Brush a thin layer of oil on both sides of the steak. Place the steak on a roasting rack set in a roasting pan. Place the pan in the oven.
Warm the steak in the oven for 15 minutes, or until it reaches 165 F.
Heat the oven to Warm and brush the steak slices with olive oil.
Lay the steak slices on a large piece of aluminum foil. Fold the edges of the foil to form a pouch.
Place foil-wrapped steak in the oven and let it warm for 15 minutes. You can check the steak temperature with the tip of a digital meat thermometer.
Heat the oven to 350 F. Bring a few cups of beef stock to a boil on the stove.
Place the steak or roast in a deep baking dish. Pour the beef stock in the dish until it reaches halfway up the sides of the meat.
Cover the dish with aluminum foil and place it in the oven. Heat the beef for 15 minutes per pound or until it reaches 165 F.