6 large-ish Yukon gold potatoes, peeled and cut into large pieces
¼ cup vegetable oil
1 teaspoon salt
1 teaspoon baking powder
3 cups flour
½ cup cold water
For the Filling
1 large onion, peeled and minced
3 tablespoons olive oil
1 teaspoon salt
½ teaspoon pepper
1. In a large pot of water, boil the potatoes until they’re cooked through. Drain and mash.
2. Remove 1 cup of the potatoes, for the dough, and set aside the remaining potatoes.
1. In a bowl, combine the flour and baking powder.
2. In a separate bowl, add the oil to the reserved cup of potatoes, and combine. Add in 1 cup of the flour mixture, and mix well. Add the remaining flour mixture and combine.
3. Make a well in the dough, and add the cold water. Knead the dough until it comes together. Let the dough rest in a bowl for 30 minutes, with a damp towel or paper towel on top.
Preheat the oven to 425°.
The filling (while the dough is resting)
1. In a skillet over a medium heat, add the olive oil and sauté the onion until it’s soft and golden, approximately 20 minutes.
2. Add in the remaining mashed potato (approx 1 ½ cups)
3. Season to taste, as needed, with salt and pepper
Put it All Together
1. Flour a work surface and rolling pin. Cut to dough into 4 equal pieces. Roll each one to 1/4” thickness, either round or rectangular.
2. Put the filling in the middle of the dough pieces, and fold the up the sides to seal.
3. Beat the egg, and add in 1 tablespoon of water.
4. Brush the egg on top of the dough. Bake, with the seams on the bottom, until golden brown, approx 20-25 mins.
Yield: 4 large knishes, or a bunch of small ones.
Optional: roll out into a long oval. Fill w/filling, and roll over like a log. Bake as a long knish, and slice after baking.
You can also substitute gluten-free flour to make a very nice knish.