Classic Baked Potato Knish

Yields: About 12-15 knishes
Prep time: 1 hour
Cook time: 45 minutes
Ingredients

For the Potato Filling:

900 g Russet or Yukon Gold potatoes (about 4-5 medium), peeled and quartered

1 large yellow onion (approx. 200-250g), finely diced

30 ml schmaltz (rendered chicken fat) - traditional and flavorful

OR 45 ml vegetable oil or unsalted butter

1 large egg, lightly beaten

5 g salt (or to taste, about 1 tsp)

2 g freshly ground black pepper (about ½ tsp)

Optional: 1 tsp of garlic powder, a pinch of nutmeg, or 2 tbsp chopped fresh dill or chives

For the Dough:

315 g all-purpose flour, plus more for dusting

5 g baking powder (about 1 tsp)

5 g salt (about 1 tsp)

1 large egg

120 ml vegetable oil

120 ml warm water

5 ml white vinegar or lemon juice (about 1 tsp)

For Assembly:

1 egg, beaten with 5 ml water (for egg wash)

Coarse sea salt, for sprinkling

Instructions

Part 1: Make the Filling

Cook the Potatoes: Place the peeled and quartered potatoes in a large pot of salted cold water. Bring to a boil and cook for 15-20 minutes, or until very tender when pierced with a fork.

Caramelize the Onions: While the potatoes are cooking, heat the schmaltz or oil in a large skillet over medium heat. Add the diced onions and cook, stirring occasionally, until they are deeply golden brown and caramelized (about 15-20 minutes). Do not rush this step—this is where a lot of the flavor comes from!

Mash and Combine: Drain the potatoes well and return them to the warm pot. Mash them until smooth. Let them cool for a few minutes.

Finish the Filling: To the mashed potatoes, add the caramelized onions (with all the fat from the pan), the beaten egg, salt, pepper, and any optional seasonings. Mix thoroughly until everything is well combined. Set the filling aside to cool completely. (A warm filling will make the dough difficult to work with.)

Part 2: Make the Dough

Combine Dry Ingredients: In a large bowl, whisk together the flour, baking powder, and salt.

Combine Wet Ingredients: In a separate medium bowl or a liquid measuring cup, whisk together the oil, warm water, 1 egg, and the vinegar.

Form the Dough: Create a well in the center of the dry ingredients. Pour the wet ingredients into the well. Using a fork or your hands, mix until a shaggy dough forms.

Knead: Turn the dough out onto a lightly floured surface. Knead gently for about 2-3 minutes, just until the dough becomes smooth and soft. Be careful not to over-knead.

Rest: Form the dough into a ball, wrap it in plastic wrap, and let it rest at room temperature for at least 30 minutes. This allows the gluten to relax, making it easier to roll out.

Part 3: Assemble the Knishes

Preheat Oven: Preheat your oven to 190°C (375°F). Line a large baking sheet with parchment paper.

Roll the Dough: On a lightly floured surface, roll the dough out into a large, thin rectangle (about 3-4 mm thick or roughly 40x50 cm). Don't worry if it's not perfect!

Form the Log: Spread the cooled potato filling evenly over the dough, leaving a 2.5 cm border along one of the longer edges.

    Pro Tip: For easier handling, you can chill the filling for 30 minutes to make it firmer.

Roll it Up: Starting from the long side with filling all the way to the edge, gently but tightly roll the dough over the filling, like a jelly roll. When you reach the end, pinch the bare edge to seal it.

Shape and Cut: Roll the log so the seam side is down. Now, gently squeeze and roll the log to elongate it slightly and make it even. Using a sharp knife or a bench scraper, cut the log into 5 cm thick pieces.

Form the Knishes: You have two options here:

    Round "Puck" Style (Classic): Take a cut piece and pinch the bottom (the cut sides) together, creating a small "belly button" on the bottom. Place it pinched-side down on the baking sheet. It will look like a little puck.

    Square "Pinwheel" Style: Simply place the cut pieces directly on the baking sheet with the spiral facing up.

Egg Wash: Brush the tops and sides of each knish generously with the egg wash. This will give them a beautiful golden, shiny finish. Sprinkle with a little coarse sea salt.

Part 4: Bake and Serve

Bake: Bake for 35-45 minutes, or until the knishes are puffed and a deep, golden brown color.

Cool and Serve: Let them cool on the baking sheet for at least 10-15 minutes before serving. They are delicious warm or at room temperature.

Serve with: Spicy brown mustard is the classic and essential accompaniment!

Metric System Notes for Baking:

Weight vs. Volume: Using grams (g) for flour is much more accurate than using cups, as it is not affected by how much you pack the flour. This leads to more consistent results.

Oven Temperatures: All ovens have slight variations. Using an oven thermometer is the best way to ensure accurate temperature.

Potato Size: The weight of the potatoes (900g) is a more reliable guide than the number of potatoes, as sizes can vary widely