Cheddar Cheese and Potato Pierogi

Make the Dough: Place 1¾ cups of the flour in a large bowl and keep the remaining ¼ cup handy. In another bowl, whisk together the egg, 3 tablespoons sour cream, 2 tablespoons melted butter, warm water, and ½ teaspoon salt. Add the egg mixture to the flour and mix until all the liquid has been absorbed. Work the dough with your hands into one manageable ball. If the dough is wet and sticky, work in some of the remaining flour, a little at a time, until it no longer sticks to your fingers.

Place the dough on a floured surface and knead for 2 to 3 minutes. The dough will be some-what firm and smooth. Return the dough ball to the bowl, cover, and let it rest for at least 30 minutes, preferably 2 hours.

Make the Filling: Place the potatoes in a small pot, pour in enough water to cover, and bring to a boil over high heat. Cover, reduce the heat to medium, and simmer until fork-tender, about 30 minutes. Drain the potatoes and place them on a folded kitchen towel. Once they are cool enough to handle, peel off their skins, place the flesh in a large bowl, and mash until mostly smooth.

Melt the 2 tablespoons butter in a medium skillet over medium heat. Add the onion and stir frequently until golden brown, about 8 minutes. Mix the onion into the mashed potatoes and set aside to cool.

Add the Cheddar cheese, egg yolk, salt, and pepper to the cooled potato mixture and mix well.

Assemble the dumplings: Before assembling the pierogi, review the Half-moon fold.

Line a tray with a kitchen towel and sprinkle with a little flour. Have ready the dough and the filling.

Knead the dough once or twice on a floured surface, divide it into 4 equal pieces, then set 3 of them aside under a kitchen towel. Shape the remaining piece into a ball and roll it out until it’s about 1/8 inch thick. Sprinkle with flour if it gets sticky.

Using the cookie cutter, cut out as many rounds as you can, usually 8 to 10. Collect all scraps from around the rounds and put them aside under a damp kitchen towel for later use.

. Lay flat 1 to 5 dough rounds. Brush each round with a very thin coating of water to make it sticky enough to seal. Center a rounded teaspoon of filling on top of each round, fold each neatly in half, pushing out any air, and pinch to seal. Dab a little water along the edges, if needed, for a better seal. Place the assembled dumplings in a single layer on the prepared tray and keep them covered with a kitchen towel while you work. Once you have assembled the first batch of dumplings, continue with the remaining dough and filling. Combine all the dough scraps, knead them into a ball, roll it out, cut out as many rounds as you can, and fill and fold those too.

. Cover the tray of assembled dumplings and place in the refrigerator for 30 to 60 minutes before cooking. Chilling them helps to set the dough, making the dumplings firm and toothsome when cooked instead of puffy and soft. Set aside the number of dumplings that you would like to cook and keep the rest frozen for up to 6 months (see page 36).

. Cook the dumplings: Fill a large pot halfway with salted water and bring it to a boil over high heat. Reduce the heat to medium for a steady simmer.

. Gently drop up to 20 dumplings, a few at a time, into the simmering water. Stir gently to prevent sticking. Cook until all of them are floating, about 3 minutes, then cook for 2 minutes longer. (If cooking frozen pierogi, add them directly to the simmering water and increase the cooking time by 1 minute. Do not allow the pierogi to thaw before cooking.)

. Remove the dumplings with a slotted spoon, place them in the large bowl, and drizzle with a ladle of the cooking liquid to prevent sticking. Cook the remaining dumplings and place them in the bowl with another ladle of the cooking liquid.

. Drain the pierogi and place them in a large, shallow serving bowl. Drizzle the dumplings with melted butter, spoon sour cream over the top, sprinkle with chives, and serve.