This is great to make when you can pick up a bag of potatoes as a loss leader. And they make great no-fuss side dishes for meals.

Bag of potatoes
Milk
Butter

Boil potatoes until soft. Mash with milk and butter. Depending on how large the bag is, you may want to split it up into batches to mash. Scoop into muffin tins and freeze. Once frozen, remove from muffin tins and keep in a freezer bag.

To serve: Defrost and heat as many servings as you need (one "muffin" equals one serving).