3 pounds russet potatoes – peeled and cut into 2-inch chunks
3 quarts water – cold
2 tablespoons kosher salt
8 tablespoons unsalted butter
1 cup whole milk
0.5 teaspoons black pepper – freshly ground
Instructions
Peel the russet potatoes and cut into 2-inch chunks, about 10 minutes.
Put the potatoes in a large pot, add the cold water and kosher salt, and bring to a boil over high heat, 8–10 minutes.
Reduce to a steady simmer and cook until a knife slides through a piece with little resistance, 15–20 minutes.
Meanwhile, warm the whole milk with the unsalted butter in a small saucepan over low heat until the butter is melted and the mixture is steaming, 2–3 minutes; keep warm.
Drain the potatoes well and return them to the dry pot over low heat; shake or stir until the surfaces look dry and steamy, 1–2 minutes.
Mash the potatoes with a potato masher or press through a ricer until mostly smooth but not gluey, 1–2 minutes.
Pour in about three-quarters of the warm milk–butter mixture and fold gently with a spatula, adding more as needed until creamy and spreadable, 1–3 minutes.
Season with the black pepper, taste, and adjust seasoning as needed; serve hot.