I have peeled, cut up, boiled, then mashed with nothing added. Then I put them in quart zip lock bags and freeze.(Make sure you get all the air out of the bags.) when I want to use them, I put then in a big bowl or dish with cool water to thaw enough to squeeze them out of the Baggie, then I can add whatever I need to use them for soup, potato pancakes, mashed, shepherds pie, etc. Just remember to reheat slowly or you get fried mashed potatoes.