Recipe Instructions:
2 pounds Russet or Yukon Gold potatoes, peeled
3 cups water
2 1/2 teaspoons kosher salt, divided
4 tablespoons (½ stick) butter, melted
6 tablespoons whole milk, warmed
2 teaspoons malt vinegar, plus more to taste
Flaky salt, to sprinkle on top
Chop each potato into sixths or eighths, trying to keep the pieces about equal in size. Add these to a pot, along with the water and 2 teaspoons salt. Set on the stove over medium-high heat to come to a boil. Cook the potatoes for 10 to 15 minutes, until you can easily break apart a piece with a fork.
When the potatoes are cooked, drain them, then add them back to the hot pot on the stove, but with the heat off. Mash the potatoes with a masher (or, if you don’t have one, a big fork), until they’re as broken down as possible. Add the melted butter and stir until smooth-ish. Add the milk and stir again. Now add the vinegar and remaining ½ teaspoon salt. Stir, then taste. More salt, vinegar, or butter? More milk to thin out? Adjust accordingly.
Serve immediately with a pat of butter and flaky salt on top. You can also keep these warm on top of a double boiler, or reheat them (adding more milk as needed) just before serving.