The First Step You Can't Skip Before Reheating Steak
Reheating steak isn't quite as tricky as making it in the first place, but it does take some attention to detail to make sure it comes out almost as tasty as when it was freshly cooked. While it's tempting to nuke your meat just like you would with other leftovers, be sure to stay away from the microwave in this case. Whether you reheat steak using the oven, stove, or air fryer, you'll want to think ahead and bring your beef to room temperature beforehand.
What does this accomplish? If you bring a chilled steak from the refrigerator straight into a sizzling hot pan, you end up essentially shocking the meat. The fibers in the beef will tense and become stiff, which can make your final product tough and chewy. The outside will also warm up much faster than the center, so you risk uneven heating. Plus, a cold steak can quickly stick to a hot pan — so when you go to flip it, the tasty brown outer layer that you worked so hard to sear can separate from the rest of the meat. It can also waste a little time in the kitchen if you don't bring your meat to room temperature ahead of time, since a frigid steak will cool down a hot pan, so you'll need to wait for it to warm up again.
Leave your steak out for two hours max
While it's a good idea to bring steak to room temperature before reheating it, you'll still want to stick to food safety guidelines. According to the U.S. Department of Agriculture, meat shouldn't be left out for more than two hours, or one hour if it's hotter than 90 degrees Fahrenheit outside. Luckily, steak only takes about an hour to fully come to room temperature from the fridge. If you're planning on using the oven, simply lay your beef on a wire rack placed over a baking sheet, which is how you'll want to cook it for even air circulation. If you're opting for a pan or air-fryer, however, you can simply lay it on a cutting board. Ideally, you'll have time to let it warm up for a full hour before reheating, but if not, even 20-30 minutes can help.
Another way to optimize your leftover steak is to re-season it. You don't need to add much, but the flavors can wither away in the cold chamber of the fridge, so a little dash of salt and pepper can liven things up a bit. Then, especially if you're going with the oven and stove-sear combination method, pat your room-temperature steaks with paper towels before heating for the best browning results.