Have "Instant" Mashed Potatoes by Freezing Leftovers
Mashed potatoes keep OK in the fridge, but to make them last longer and so you can enjoy some any time, here's what to do.
Rather than throwing leftover mashed potatoes away, freeze them! Use a scoop to portion the potatoes onto a parchment-lined baking sheet, freeze until solid, then transfer to a large resealable plastic bag. To reheat them, microwave on high for 1 minute, or until heated through.
Another option: The next time you make mashed potatoes, fix extra and use them to make duchess potatoes. Add 1 beaten egg to every 2 cups of mashed potatoes, then pipe or mound onto a parchment-lined baking sheet. Freeze until firm, then transfer to a plastic bag, and keep frozen up to 3 months. To use, place frozen potatoes onto a greased baking sheet and drizzle with melted butter. Bake at 375° for 25 minutes, or until heated all the way through with edges turning crispy and brown. This also works with mashed sweet potatoes.