Learn to make potato knishes, that favorite Jewish deli snack, at home. While this recipe is a bit of a project, you can make all of the elements in advance and spread out the work over a few days.
If Jewish food has a reputation for being heavy, it is probably because of dishes like the potato knish. For the uninitiated, a potato knish is savory baked dumpling that consists of pastry wrapped around a mashed potato filling. In other words, a knish is not for anyone avoiding carbs! But they are certainly are delicious.
Like many classic Jewish deli foods, the knish is an American invention. It was not something people ate back in eastern Europe or Russia – the places where many Jews emigrated from. Rather, the knish is a food that was invented in the delis of New York City as an inexpensive yet filling food for workers to eat on the go.
Fillings For Knishes
The most traditional fillings for knishes are potato, obviously, and also kasha, which is a type of porridge made from buckwheat groats. But more modern versions can also include broccoli, spinach, or mushroom. I have even seen pizza-flavored knishes! You can also find sweet knishes that are filled with fruit and a soft, mild cheese.
A hundred years ago, there were many shops and even pushcarts selling knishes all over New York City, especially the Lower East Side of Manhattan and Brooklyn. Today, hot dog carts and other street food vendors in New York are no longer permitted to sell knishes and many of the famous knisheries have closed their doors, making a good knish much harder to find than it used to be.
One iconic knish store that remains open, and is worth a visit the next time you are in New York City, is the Yonah Schimmel Knish Bakery on the Lower East Side. It has been in the same location since 1910! You can even order these massive knishes for nationwide delivery through Goldbelly.
How To Make Your Own Potato Knish
But assuming you can’t get to New York anytime soon – and don’t want to pay Goldbelly prices – your best bet is to make your own knishes, and it is surprisingly easy to do so. The dough for the pastry shell is simple to make and is quite forgiving to work with. The most important thing to know is that after you make the dough, you need to let it rest for at least an hour before rolling it out. You can also prepare it in advance and refrigerate it until needed.
Making the potato filling is a bit time-consuming, but as I mentioned, you can also prepare it in advance, which spreads out the work. The filling requires two main ingredients: mashed potato and caramelized onion, which provides most of the flavor as well as a hint of sweetness. It is best to use starchy Russet or baking potatoes for the mashed potatoes and cook them in boiling salted water until tender enough to mash.
For the caramelized onions, regular yellow onions work perfectly. The trickier question is which fat you want to use to sauté the onions. The most traditional fat would be schmaltz, which is rendered chicken fat. It adds amazing flavor to the onions, but it may be hard to find. And using schmaltz means that your knishes will not be suitable for vegetarians. If you have a hard time finding schmaltz, or prefer a vegetarian knish, you can use butter or a neutral-flavored oil, like vegetable or canola oil, which has the added benefit of keeping the knishes dairy-free.
How To Form Knishes
Knishes come in many shapes and sizes. Sometimes they are thin and square – although this variety of knish is usually fried, not baked. Sometimes they are round with the pastry covering the filling completely. The knishes that I grew up eating, however, were round with an opening at the top that allows the filling to peek through. This is the classic Jewish deli style, so that is my preference.
To form the knishes, you first roll out the rested dough until it is quite thin and in the shape of a rectangle. Then, you place the filling near the bottom edge of the dough in the shape of a log and roll it up so that there are several layers of the dough wrapped around the filling. Next, you cut the dough log into pieces to form the individual knishes. At this point, the knishes will be open on the top and bottom. You can leave them like this or, if you prefer, you can stretch the dough to cover one end, which will become the bottom of the knish – leaving the top open to expose the filling within.
Lastly the knishes are given a brushing of egg wash to ensure a nice golden finish and baked in the oven. If time permits, I recommend chilling the formed knishes prior to baking. The mashed potato filling expands when baked and this can cause the dough to split open. Chilling the formed knishes helps minimize cracking and splitting. Alternatively, try to roll the dough loosely around the filling leaving some room for the filling to expand. (If your knishes do split open, do not worry. They will still taste amazing.)
Serving Potato Knish
Knishes are best served warm with a generous dollop of spicy brown mustard. The classic thing to drink with a potato knish is a glass of buttermilk or kefir, which is a kind of drinkable yogurt. The tanginess of these dairy-based liquids cuts through the richness of the knish and provides some much-needed acidity. My husband, who grew up going to the famous and sadly defunct Mrs. Stahl’s Knishes in Brooklyn, swears by the knish-buttermilk combination. Give it a try!
While knishes are typically thought of as a snack, they are certainly substantial enough to serve as a meal. I especially like to serve knishes at brunch. Or try them as a side dish for brisket or roast chicken. Any leftover knishes – because it is hard to eat more than one at a time – can be stored in the refrigerator and reheated in a 350 degree oven until warmed through.Print
- 2 and ½ cups (350 g) all-purpose flour
- 1 tsp. baking powder
- ½ tsp. fine sea salt
- 1 egg
- 1 tsp. white vinegar
- ½ cup neutral oil such as vegetable or canola
- ½ cup warm water
- 2 lbs. Russet or baking potatoes, peeled and cut into 2-inch chunks
- 3 tsp. kosher salt, divided
- 3 Tbsp. butter, oil, or schmaltz*
- 2 yellow onions, thinly sliced
- ½ cup scallions, sliced
- ½ tsp. white pepper
- 1 egg beaten with 1 Tbsp. of water
- In a large bowl, whisk together the flour, baking powder, and salt. Whisk together the egg, vinegar, oil, and water in a small bowl or large measuring cup. Add the wet ingredients to the dry ingredients and stir with a fork until a shaggy dough forms.
- Turn the dough out onto a lightly floured surface and knead until smooth, but do not overwork the dough. Cover and set aside to rest for at least 1 hour. (May be done up to 3 days in advance. If making the dough in advance, refrigerate it until needed.)
- While the dough is resting, prepare the filling. Place the pieces of potato in a large, heavy Dutch oven or saucepan and cover with cold water. Add 2 teaspoons of salt to the water. Cover and bring to a boil over high heat. When the water is boiling, partially uncover the pot and turn the heat down to medium. Cook the potatoes until they are tender, about 10 minutes, and then drain them well. When the potatoes are dry, return them to the pot and mash them with a potato masher or put them through a potato ricer. Set aside.
- While the potatoes are cooking, caramelize the onions. Heat the butter, oil, or schmaltz over medium heat in a large, deep skillet with a tight-fitting lid. Add the sliced onions and season with the remaining teaspoon of salt. Stir to coat the onions with the fat and then turn the heat down to low. Cover the onions and cook, stirring occasionally, for 10 minutes. Uncover the skillet and continue to cook the onions, stirring frequently until very brown and soft, about 15 minutes.
- Add the mashed potatoes and scallions to the skillet with the onions and stir to combine. Add the white pepper and taste, adding more salt if necessary. Allow the filing to cool to room temperature. (May be done up to 3 days in advance. If making the filling in advance, refrigerate it until needed.)
- Line two baking sheets with parchment paper. To assemble the knishes, divide the rested dough in half. Place one half of the dough on a lightly floured surface and roll out into a 12×16 rectangle with one of the long sides facing you. Arrange half of the potato mixture in a log along the bottom of the dough, about 2 inches from the edge. Pull the bottom edge of the dough over the potato mixture and roll away from you, loosely, so there are multiple layers of dough around the potato filling.
- Using a serrated knife, cut the log of dough into six even pieces. Turn each piece 90 degrees so the exposed filling is on the top and bottom. If desired, pull the edge of the dough over the bottom of the knish and pinch it closed. Place the knishes, closed side down, on one of the parchment-lined baking sheets. Repeat this process with the remaining half of the dough and the remaining potato filling.
- If time permits, chill the formed knishes, covered, for several hours, and up to overnight, prior to baking. When ready to bake, preheat the oven to 375°F. Brush the outside of the knishes with the egg wash.
- Bake knishes until the pastry is golden brown, about 40 minutes. Serve warm with spicy brown mustard.
*Note: Schmaltz, which is simply rendered chicken fat, is a traditional ingredient in eastern European Jewish cooking. You can make your own or look for it at gourmet markets or grocery stores, where it is sometimes sold frozen. You can also substitute duck fat if that is easier to find. Using schmaltz will prevent this dish from being meatless. To keep the dish vegetarian, use butter and for a dairy-free version, use oil.