Use potatoes of approximately the same size so they’ll all be finished cooking at the same time. Alternatively, cook different types of potatoes separately or cut them so that they’re about the same size.
Serves 4 to 6
1/2 pound new red potatoes, cut into 1-inch pieces
1/2 pound new yellow potatoes, cut into 1-inch pieces
1/2 pound new purple potatoes, cut into 1-inch pieces
Kosher salt
2 to 4 tablespoons unsalted butter
Freshly ground black pepper
2 tablespoons chopped fresh flat-leaf parsley
Fill a 4-quart pot with cold water. Add about 1 tablespoon of kosher salt per quart of water—it should taste like the ocean. (If using finely ground sea salt or table salt, use 1 1/2 teaspoons per quart of water.) Add the potatoes, bring to a boil, reduce to a simmer, cover and cook until the potatoes are tender, 10 to 15 minutes. Drain the potatoes and return them to the pot. Toss with the butter and additional salt and pepper to taste. Toss with parsley; serve hot.