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Spinach Potato Knishes Recipe
Victoria Haneveer

Spinach Potato Knishes

Homemade knish dough wraps around a filling of potato, spinach, browned onions and garlic. These large knishes are baked until golden and served warm with spicy mustard.
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Prep Time 25 minutes
Cook Time 1 hour 30 minutes
Chilling and Resting Time 4 hours 40 minutes
Total Time 6 hours 35 minutes
Servings: 6 large knishes
Course: Appetizer, Snack
Cuisine: Jewish
Ingredients Method Notes

Ingredients
 

For the Knish Dough
  • 1 ½ cups (185g) all-purpose flour (plain flour), plus more for dusting
  • 3 tablespoons extra-virgin olive oil, plus more for brushing
  • ¼ cup plus 2 tablespoons (90ml) cold seltzer water
  • 2 teaspoons apple cider vinegar
  • 1 teaspoon kosher salt
  • Freshly ground black pepper, as needed
For the Spinach Potato Filling
  • 1 ½ pounds (680g) medium russet potatoes, about 3
  • Kosher salt and freshly ground black pepper, as needed
  • 16 ounces (450g) frozen whole-leaf or cut-leaf spinach, thawed
  • 4 tablespoons extra-virgin olive oil, plus more for brushing
  • 2 medium yellow onions, finely diced
  • 4 garlic cloves, minced
  • ¼ cup (60ml) heavy cream, warmed
  • Spicy mustard, to serve

Equipment

  • Food processor
  • Large saucepan
  • Large skillet
  • Clean kitchen towel
  • Potato masher
  • Rolling Pin
  • Parchment paper
  • Baking sheet
  • Pastry brush
  • Sharp knife
  • Wooden spoon

Method
 

  1. Add the flour to a food processor. Pulse while slowly pouring the 3 tablespoons of olive oil through the feed tube. Scrape down the bowl and pulse again.
  2. Combine the cold seltzer and apple cider vinegar in a measuring cup. Stir in 1 teaspoon kosher salt until dissolved. With the food processor running in pulses, pour the liquid into the flour mixture over about 20 to 30 seconds.
  3. Tip the dough onto a lightly floured surface and knead for about 1 minute, until smooth. Flatten it into a disk, wrap tightly in plastic wrap and refrigerate for at least 2 hours.
  4. Put the unpeeled potatoes in a saucepan and cover them with water. Season the water generously with salt. Bring to a boil, then reduce the heat and simmer for 35 to 40 minutes, until a fork slides easily into the center. Drain and let them cool until you can handle them.
  5. Put the thawed spinach in a clean kitchen towel and squeeze out as much liquid as possible. Roughly chop the drained spinach.
  6. Heat 3 tablespoons of the olive oil in a large skillet over medium heat. Add the onions with ¼ teaspoon salt and ¼ teaspoon black pepper. Cook for about 15 minutes, stirring occasionally, until browned. Add the garlic and cook for another 2 minutes.
  7. Add the spinach, ½ teaspoon salt and ¼ teaspoon black pepper. Stir well, then remove the skillet from the heat.
  8. Take the dough from the refrigerator and leave it at room temperature for 30 to 45 minutes, until pliable.
  9. Peel the cooled potatoes using the side of a spoon and add them to a large bowl. Add the warmed cream and remaining 1 tablespoon olive oil. Mash coarsely, then fold in the spinach mixture. Taste and add more salt or black pepper if needed.
  10. Position an oven rack in the middle and preheat the oven to 375°F (190°C). Lightly brush a baking sheet with olive oil.
  11. Set the dough on a floured sheet of parchment paper and dust the top lightly with flour. Stretch it into a 6 x 8-inch (15 x 20cm) rectangle, then use a rolling pin to make a 12 x 18-inch (30 x 46cm) rectangle.
  12. Arrange the filling in a compact log about 14 x 2 inches (36 x 5cm), leaving a 2-inch (5cm) border along the edge nearest you and at both ends.
  13. Use the parchment paper to help roll the dough tightly around the filling. Brush away excess flour as you work and gently stretch the dough where needed.
  14. Pinch the center seam closed and set the roll seam-side down. Twist and seal each end, then pinch off any excess dough.
  15. Use the handle of a wooden spoon to press the log into 3 equal sections. Slice at the indentations and check that the ends are securely sealed.
  16. Cut each of the 3 sections in half crosswise to make 6 knishes. Arrange them cut-side up on the baking sheet, about 2 inches (5cm) apart. Press each one gently into a disk about 1 ½ inches (4cm) thick.
  17. Bake for 30 minutes. Brush the knishes generously with olive oil, then bake for another 25 to 35 minutes, until golden.
  18. Let them cool slightly and serve warm with spicy mustard.

Notes

  • Squeeze the thawed spinach very thoroughly before adding it to the filling.
  • The potatoes are cooked in their skins and peeled after cooking.
  • Cut the 3 filled sections crosswise, not lengthwise, to make the 6 individual knishes.
  • The dough needs at least 2 hours in the refrigerator and another 30 to 45 minutes at room temperature before rolling.
  • Serve the knishes warm with spicy brown mustard.