Place leftover mashed potatoes in a medium pot or saucepan with about ¼ cup milk per 2 cups potatoes.
Cook over medium low heat while stirring, approximately 5-7 minutes depending on how many potatoes you have.
Season with salt and pepper and top with butter if desired.
Notes
1. MicrowaveWhile we love the microwave for reheating many sides, if you have lots of mashed potatoes, it can be less than ideal. That being said, we do turn to the microwave since it's quick!To reheat mashed potatoes in the microwave, pour a little bit of milk on top and reheat at 70-80% power for about 3 minutes for every 1 1/2 cups of potatoes. Stir them every minute. Depending on the wattage of the microwave and the shape of your dish, this can vary so check them early.2. OvenReheating in the oven makes them just like new but it takes a lot more time. We bake them at 350°F for about 20-25 minutes (with a splash of milk on top). Give them a stir and make sure they're hot. If you have a really full pan, they might need a little bit more time.3. Frying PanThis is a brunch favorite! Heat some oil in a pan and add the potatoes and press them into a thin layer. Let them cook undisturbed for about 5-7 minutes. Stir and continue letting them cook until heated through. This method produces a mashed potato with a little bit of a crisp to it and we can't get enough! Add in your other leftovers to make a bubble and squeak or top them with poached eggs.