These hearty and delicious doughy-potatoey bundles are a traditional Jewish delicacy. However, full-disclosure, they wouldn’t be served at an observant Passover meal, because chametz (anything containing grain that has come into contact with water and risen) must be avoided at Passover. However, since we are not attempting an observant Passover meal, and they are amazing, we like to have these. They are great with applesauce, sour cream, or spicy mustard. A more authentic, chametz-free choice would be potato latkes.
- 2 1/2 cups All-Purpose Flour
- 1 tsp Baking Powder
- 1/2 tsp Salt
- 1 Large Egg
- 1/2 cup Vegetable Oil
- 1 tsp White Vinegar
- 1/2 cup Water
- 1 1/2 pounds Russet Potatoes (~ 3 medium, peeled and quartered)
- 1 Yellow Onion (peeled and diced)
- 1 tbsp Oil (vegetable or olive)
- 1 tbsp Butter (unsalted)
- 1/2 tsp Table Salt
- Black Pepper (freshly ground)
- 1 Large Egg Yolk
- 1 teaspoon Water
Make the dough:
- Stir together your dry ingredients in the bottom of a medium/large bowl. In a small bowl, whisk together the egg, oil, vinegar, and water. Pour it over the dry ingredients and stir to combine. Once the mixture is a craggy, uneven mass, knead it until smooth, about a minute. Wrap the dough in plastic wrap. Set it aside for an hour (or in the fridge, up to 3 days) until needed.
Prepare the filling:
- Put the potatoes into a large pot, cover with cold water, and bring to a boil over high heat. Reduce the heat to medium and cook until the potatoes can be pierced easily with a knife, about 20 minutes. Drain, then transfer to a large bowl to cool.
- Heat a large, heavy skillet over medium heat. Once hot, add the butter and oil and once they’re fully melted and a bit sizzly, add onions and reduce the heat to medium-low. Cook, stirring frequently, until deeply caramelized, about 45 minutes. Transfer to the bowl with the potatoes and mash with a potato masher until almost smooth. Stir in the salt and 10-20 grinds of black pepper and set the filling aside.
- Line a large baking sheet with parchment paper and preheat your oven to 375°F.
- If the dough has sweated some beads of oil while it rested, knead it back into an even mass. Divide the dough in half. On a well-floured surface, roll the first half of the dough into a very thin sheet, roughly in the shape of a 1-foot square. Create a two-inch thick log from half your potato filling across the bottom of your dough. Roll the filling up in the dough like a burrito, but not too tight. Keep rolling until the log has been wrapped twice in dough. Pinch and twist the ends of the log. Repeat the process with the second half of your dough and the second half of the filling.
- Make indentations on the logs with a table knife to divide them into thirds. Pick up the end of a log and squeeze and twist the dough a full twist at these points, separating the filling as you squeeze and twist, as if you were making sausage links. Cut the dough at each twist, then pinch the ends of each segment together to form a sealed knish. Use the palm of your hand to flatten the knish a bit into a rounded dome.
- Arrange the knishes on your prepared baking sheet so that they don’t touch. Whisk the egg yolk and water together to form a glaze and brush it over the knish dough. Bake the knishes for about 45 minutes, rotating your tray if needed for them to bake into an even golden brown color. Leave them to rest on cooling racks while you prepare the rest of the meal.