Thursday was "Polish Night" at the restaurant run by Grant Achatz's parents, with specials like sausage and sauerkraut, cabbage soup and pierogies. Those humble pierogies inspired the avant-garde ones he created as a chef, filled with a mustard sauce for the beef served on the same plate. The pierogies here, filled with mustardy mashed potatoes, pay homage to both versions. More Potato Recipes
How to Make It
In a large bowl, mix the flour with the sour cream, egg, egg yolk, butter and salt. On a lightly floured work surface, knead the dough briefly until smooth. Cover the dough with plastic wrap and let rest at room temperature for 15 minutes.
In a medium saucepan, cover the potatoes with water and boil until tender, about 12 minutes. Drain the potatoes and peel them as soon as possible. In a bowl, mash the potatoes with the sour cream, mustard and 2 1/2 tablespoons of the butter until smooth. Season with salt and pepper.
Bring a large pot of salted water to a boil. On a floured work surface, roll out the pierogi dough 1/8 inch thick. Using a 3 1/2-inch biscuit cutter, stamp out 20 rounds. Brush off any excess flour and moisten the edge of each round with water. Place a level tablespoon of the potato filling on one side of each round, leaving a 1/4-inch border. Fold the dough over the filling to form half-moons and press the edges firmly to seal.
Cook the pierogies in the boiling water until tender, about 5 minutes. Drain well and transfer to a large, shallow dish. Add a little vegetable oil and toss to coat lightly.
In a large skillet, melt the remaining 1 1/2 tablespoons of butter. Add the pierogies and cook over moderate heat, turning once, until browned, about 3 minutes per side. Transfer the pierogies to a platter. Season with salt and pepper, sprinkle with the parsley and serve.