The trick to reheating any kind of meat is to keep the moisture levels in balance. Some methods—such as the microwave, which works by heating up the water in a food—will keep meat moist, but make it unpleasantly soft. Other methods, such as the oven, can dry meat out if you're not careful, making it tough and chewy.
1. Take the chicken out of the fridge 20 to 30 minutes before reheating.
In order to reduce the amount of time the chicken spends in the oven (and thus, reduce the chances that it will dry out), you want to let it come up to room temperature.
2. Place chicken on a wire rack and preheat oven to 400°F.
We recommend using a wire rack on a sheet pan to keep the chicken raised up off the pan. This will let air circulate and will keep the bottom of the breading from turning mushy. If you need to purchase a wire rack, here’s one we recommend.
3. Bake chicken for 12 to 20 minutes.
In general, we’ve found the chicken is ready when it reaches an internal temperature of 120°F. That’s hot enough to taste good without drying out. And as long as you eat it right away, it won't be in the danger zone for long enough to be unsafe.