There are a few different ways to reheat chicken, but the best way really depends on how the chicken was cooked in the first place. If the chicken was cooked in a sauce, then the best way to reheat it is on the stove over low heat until it is heated through. If the chicken was roasted, then the best way to reheat it is in a 325 degree oven until it is heated through. And if the chicken was grilled, then the best way to reheat it is on a stove over medium heat until it is heated through.