Peel and cut the Russet Potatoes into even 1–2 inch chunks so they cook uniformly.
Place the potatoes in a large pot and cover with cold water; add a generous pinch of Kosher Salt and bring to a boil over high heat, then reduce to a simmer until the potatoes are fork-tender, about 15–20 minutes.
While the potatoes cook, gently warm the Whole Milk with the Unsalted Butter in a small saucepan or in the microwave until the butter is melted and the mixture is warm (do not boil).
Drain the potatoes thoroughly and return them to the hot pot; let them sit off the heat for a minute so excess moisture evaporates.
Mash the potatoes using a potato masher or pass them through a ricer for an extra-smooth texture. Gradually stir in the warmed butter-and-milk mixture until the mash reaches your desired creaminess.
Season to taste with additional kosher salt and freshly ground Black Pepper, tasting and adjusting until balanced.
Serve the mashed potatoes hot, optionally topping with an extra pat of butter or a drizzle of warm milk for sheen.
