Mara Moorhead's Potato Knishes
2 1/2 cups all-purpose flour
1 teaspoon baking powder
1/2 teaspoon table salt
1 large egg
1/2 cup vegetable oil
1 teaspoon white vinegar
1/2 cup water
1 1/2 pounds (about 3 medium) potatoes, peeled and cut
1 medium onion (yellow or sweet) diced
2 tablespoon vegetable or olive oil
2 tablespoon unsalted butter (or margarine)
Freshly ground black pepper
1 egg for egg wash
Place flour, baking powder and salt in food processor. Pulse to combine. Add egg, oil and vinegar. With processor running, slowly add water until dough just comes together. Turn dough onto lightly floured surface and knead until smooth (about 1 minute). Place
dough in a bowl, cover with plastic and let rest while you prepare the filling. (Dough can also be put in fridge for a few days until ready to use.)
Place potatoes into a large pot, cover with cold water, add a little Kosher salt, and bring to a boil over high heat. Reduce heat to medium and cook until potatoes can be pierced easily with a knife, about 20 minutes. Drain potatoes, transfer them to a large bowl and
mash or rice them. While potatoes cook, heat butter (or margarine) and oil in a sauté pan on medium-high heat. Add onion and reduce heat to medium-low. Let onions cook, stirring occasionally
until golden, about 30 minutes. Add the onions and liquid from the pan to the potatoes. Mix and season with Kosher Salt and fresh ground pepper.
Preheat oven to 375 degrees.
Divide dough in half. Shape one piece into a rough rectangle and return the other piece to the bowl. Place dough between two pieces of parchment paper and roll into a rectangle approximately 13x9 in. (This doesn't have to be exact. You just want to be
sure you roll the dough nice and thin.)
Take some of the potato mixture and form it into a two inch log on the long edge of the rectangle. Use less potato for smaller knishes, more for larger knishes. With the long edge of the dough facing you, begin rolling the knish jelly roll style. Roll the dough over the potato mixture and continue rolling until the filling is wrapped twice in the dough. Seal the ends and trim the excess dough. The excess dough can be re-rolled.
To Form Knish:
With the side of your hand, make indentations at even intervals down the roll. Continue using the side of your hand and gently press down while moving your hand back and forth in a sawing motion. This not only cuts your knish, but seals it as well. To make a
round knish, turn knish with sealed edge down. Gently press down with the palm of your hand and pull edges up to form the circle. it is fine if some potato peeks through. Place knish on parchment lined baking sheet. Brush with egg wash (1 egg whisked with a little
water). Bake at 375 degrees for 30-45 minutes until golden brown.
Knish can be made large, or small, in squares or rounds. You can form knishes and freeze them prior to baking.