Quiche can easily be frozen and reheated to enjoy later for meal prep lunches or special weekend breakfasts. To Freeze Leftovers: Freeze leftover slices by wrapping them in foil or Press n Seal. I like to then place the slices in a freezer safe Ziploc bag and label. When you are ready to eat, remove from the freezer and microwave for 2- 2 ½ minutes.