Reheating Leftovers - Kitchen Tips - as part of the expert series by GeoBeats. You may wonder what is the best way to re-heat your left-overs, so you have three choices. There is the microwave, the oven or the stove. So, the important thing is that you heat the food to the temperature that kills off any bacteria that may have have formed. Even when it is sitting in the refrigerator, bacteria can still grow, especially if the food has been there for a while. So, you want to make sure that when you are re-heating soups or stews on the stove, that they come to a boil. If you are re-heating in the oven, you may want to cover it, so it does not dry out, unless it is a slice of pizza. You do not want that to get soggy, so do not cover that. And the microwave, you can cook in the microwave, as well. Obviously, do not cover it with plastic. Then, just use a thermometer to test the temperature, after it has come out, to make sure that it is 165 degrees and then you can be sure that the food that you are about to eat, will be safe to eat.