📝 About This Recipe
A cornerstone of Eastern European Jewish soul food, these knishes feature a thin, flaky pastry wrapped around a rich, savory mashed potato filling. Caramelized onions and a hint of white pepper provide a deep, nostalgic flavor that transports you straight to a classic New York deli. Perfectly golden and impossibly comforting, they are the ultimate handheld comfort food that works as a side dish or a hearty snack.
🥗 Ingredients
For the Dough
- 2 1/2 cups All-purpose flour (plus extra for dusting)
- 1 teaspoon Baking powder
- 1/2 teaspoon Kosher salt
- 1 Large egg (at room temperature)
- 1/2 cup Vegetable oil (neutral flavor)
- 1/2 cup Warm water
- 1 teaspoon White vinegar (helps relax the gluten for a thinner crust)
For the Filling
- 2 pounds Russet potatoes (peeled and cubed)
- 2 large Yellow onions (finely diced)
- 4 tablespoons Schmaltz (chicken fat) or Butter (schmaltz is traditional for authentic flavor)
- 1 Large egg (lightly beaten)
- 1 1/2 teaspoons Kosher salt (adjust to taste)
- 1/2 teaspoon Ground white pepper (adds a classic deli spice profile)
- 1/2 teaspoon Garlic powder
For the Egg Wash
- 1 Egg yolk
- 1 tablespoon Water
👨🍳 Instructions
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1
In a large bowl, whisk together the flour, baking powder, and salt. Make a well in the center and add the egg, oil, warm water, and vinegar.
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2
Mix the dough with a wooden spoon until it comes together, then knead on a lightly floured surface for about 5 minutes until smooth and elastic. Wrap in plastic and let rest at room temperature for 30-60 minutes.
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3
While the dough rests, place the cubed potatoes in a pot of salted water. Bring to a boil and cook for 15-20 minutes until very tender. Drain well.
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4
In a skillet over medium heat, melt the schmaltz or butter. Add the diced onions and cook slowly for 15-20 minutes, stirring occasionally, until they are deep golden brown and caramelized.
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5
Mash the hot potatoes until smooth. Fold in the caramelized onions (and their fat), salt, white pepper, and garlic powder. Let the mixture cool slightly.
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6
Once the potato mixture is warm but not hot, stir in the beaten egg. This helps bind the filling so it doesn't crumble when sliced.
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7
Preheat your oven to 375°F (190°C) and line a large baking sheet with parchment paper.
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8
Divide the rested dough into two equal pieces. On a well-floured surface, roll one piece into a very thin rectangle, approximately 12x10 inches. The dough should be almost translucent.
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9
Spoon half of the potato filling in a thick log along the long edge of the dough, leaving a 1-inch border at the ends.
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10
Roll the dough tightly around the filling like a jelly roll, ending with the seam side down. Repeat with the second piece of dough and the remaining filling.
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11
Using the side of your hand (in a sawing motion), 'pinch' the long roll into 6 equal sections. This seals the ends as you cut. Twist the ends slightly and tuck them in to form a round, squat bun shape.
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12
Place the knishes on the prepared baking sheet. Whisk the egg yolk and water together and brush generously over the tops and sides of each knish.
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13
Bake for 35-40 minutes, or until the pastry is crisp and a deep golden brown.
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14
Let them rest for 5-10 minutes before serving to allow the filling to set.
💡 Chef's Tips
Don't skimp on the dough resting time; it's crucial for rolling the dough thin without it snapping back. For the smoothest filling, use a potato ricer instead of a traditional masher. If you don't have schmaltz, use butter for a vegetarian version, but avoid using only oil as you'll miss out on the rich flavor. Ensure the potato filling is cooled to at least room temperature before rolling; hot filling will steam the dough from the inside and make it soggy. To reheat, use an oven or toaster oven to maintain the crispness of the crust rather than a microwave.
🍽️ Serving Suggestions
Serve warm with a side of spicy brown deli mustard for the most authentic experience. Pair with a hot bowl of Matzo Ball soup or Borscht for a complete Eastern European meal. Accompany with crunchy garlic dill pickles to cut through the richness of the potato. Enjoy with a glass of seltzer water or a black cherry soda. Serve alongside roasted brisket or roast chicken as a hearty starch component.