Bear with me.
I make mashed potatoes the night before:
Peal lots of potatoes and bring them up to pressure and remove from stove, run cold water over lid and pour off water. [No waiting.]
Then in my large mixer bowl add butter, can milk, salt and pepper to taste, and serve. Store what is left.
Next day: take left over's add mayo, and sweet pickle relish and celery salt and serve cold.