Recipe video. This is an outrageously delicious yet highly practical way to make mashed potato ahead of time! A layer of cheese and bacon prevents the creamy mash from drying out as it reheats in the oven, while transforming this humble side into something extra-devilish and decadent. Oh the power of cheese (plus bacon)!Make it fresh, or assemble ahead and reheat when required. Serve in place of plain ole' mash.