Serves: Makes 9 or 10 rolls
- 1 small russet potato, peeled and quartered
- ½ teaspoons active dry yeast, or 1 teaspoon instant yeast
- ¼ cup sugar
- 4 tablespoons (½ stick) unsalted butter, very soft
- ½ cup warm whole milk (110° to 115°F)
- 1 large egg, at room temperature
- 2½ cups bread flour or unbleached all-purpose flour, plus more as needed
- ½ teaspoon salt
Put the quartered potato in a small saucepan, cover with water, and set over medium heat. Bring to a simmer and cook for 15 to 20 minutes, until the tip of a paring knife slides in and out easily. Drain well, reserving ¼ cup of the cooking water. Return the potato to the pan and mash using a potato masher or fork. Set aside to cool to room temperature.
Warm the potato water to 110° to 115°F and pour into the bowl of a stand mixer. Add the yeast and 1 teaspoon of the sugar and whisk by hand to blend. Allow the mixture to sit for 10 minutes, or until the yeast is activated and foamy or bubbling. Measure ¼ cup mashed potatoes and add to the bowl. Add the remaining sugar, butter, milk, and egg and whisk by hand until well blended. Add the flour and salt and knead on low speed for 2 to 3 minutes, until the dough comes together. It will seem sticky. With the mixer on low, add additional flour, a tablespoon at a time, until the dough pulls away from the sides of the bowl. Turn the speed to medium-low and continue to knead until the dough feels firm, dense, and springy, 5 to 6 minutes. Note: This dough is soft and sticky and will not pull away from the sides completely. Do not overknead or the starch from the potato will break down and make the dough gooey.
Lightly butter or oil a bowl and scrape the dough into it. Lightly coat the surface of the dough with a little butter or oil. Cover with plastic wrap or a damp lint-free cotton towel and let the dough rise until doubled in size, 45 to 60 minutes (longer if the room is cold).
Turn the dough out onto a lightly floured work surface. Press down on the dough firmly to expel some of the air bubbles. Chill, covered, for at least 2 hours and up to overnight, or until the dough is very cold.
Line a baking sheet with parchment paper or a silicone mat. Cut the dough into ⅓-cup portions and shape each into a taut, round ball. Press the dough into a flattened disk, then grab the edges and draw them up into the center, pinching all the edges together where they meet. Flip the dough over so the smooth side is up. Cup your hands around the dough and create extra tension by gently pulling the dough downward and tucking it under. Move the dough in a small circle between your cupped hands, passing it back and forth, and gently tucking around the edges to create extra tension. Position the rolls on the baking sheet about 3 inches apart.
Cover the rolls loosely with plastic wrap or a damp lint-free cotton towel and let rise until almost doubled in size, 35 to 40 minutes (longer if the room is cold).
Preheat the oven to 375°F and position an oven rack in the middle of the oven. Bake the rolls for 10 minutes. Rotate the pan and continue to bake for 10 to 15 minutes longer, until the rolls are golden brown and their internal temperature registers 200°F on an instant-read thermometer. Transfer to a cooling rack. Serve warm or at room temperature.