3 tablespoons extra-virgin olive oil
2 ounces pancetta or guanciale
3/4 pound russet potatoes, peeled and cut into 1/2-inch cubes
Kosher salt, as needed
1/2 pound spaghetti, broken in half lengthwise
1/3 cup finely grated ricotta salata, plus more for sprinkling
Freshly ground black pepper, to taste

In a large skillet, heat the olive oil and pancetta over medium heat, stirring until pancetta renders its fat. Do not let it brown or become crisp. Add the potatoes and stir for about 1 minute to coat them with fat, then add 2 cups water. Bring to a simmer and cook uncovered until potatoes are soft enough to mash, about 10 minutes. Mash to a near-puree and set skillet aside.

In a large pot, bring 3 quarts of water and 2 tablespoons salt to a rolling boil over high heat. Add the spaghetti and cook until al dente.

Just before pasta is done, return skillet to medium heat. With tongs, lift pasta from pot and transfer it, dripping-wet, to skillet. Reserve 1 cup cooking water. Toss pasta with tongs, coating pasta evenly with creamy sauce. Add the ricotta salata and a generous amount of the black pepper and toss again, thinning sauce as needed with enough pasta water to make a creamy, but not soupy, dish.

Taste for seasoning. Serve at once, topping each portion with a little additional cheese.

Makes 4 servings,

— Recipe from "My Calabria," by Rosetta Costantino (W.W. Norton).