2 pounds (900g) russet potatoes

Kosher salt

1/2 cup (120ml) whole milk, plus more as needed

6 tablespoons unsalted butter (85g), room temperature, cut into 1/2-inch pats

Freshly ground black pepper

Peel potatoes and cut into 1- or 2-inch cubes. Transfer to a pot of cold water and rinse, changing water 2 or 3 times until it runs clear. Cover potatoes with fresh cold water and season generously with salt.

Set the pot over medium-high heat and bring to a boil, then reduce heat to maintain a gentle simmer. Cook until potatoes are completely tender, about 15 minutes after reaching a simmer.

Drain potatoes in a colander and rinse under hot running water for 30 seconds to remove excess starch. Let them steam for 1 minute to remove moisture.

Using a ricer or food mill, pass potatoes through into the now-empty pot.

Add butter and gently fold it into the potatoes until incorporated.

Mound potatoes in the center of the pot and pour milk around the edges. Set over medium heat and bring milk to a simmer before folding it into the potatoes.

For creamier potatoes, add more milk using the same method—pouring around the edges, simmering, and folding in.

Season with salt and freshly ground black pepper to taste. Serve warm.