3 c flour
1 c water
1/2 c vegetable oil
1 tbsp vinegar
4 peeled and boiled potatoes
1 c stock or milk
1 chopped onion
Salt + pepper
Roast the chopped onion in 3 tbsp olive oil until golden brown. Rice the potatoes and mix in the roasted onions and oil in which they cooked. Add milk or stock until the consistency is of thick mashed potatoes. Season with salt and pepper.
Mix all the dough ingredients and kneed until consistent. Roll out and than stretch dough out on a tea towel until paper thin, taking care to keep it a consistent thickness and not to make holes. Line the long end of the dough with filling. Roll dough starting with the end with the filling on top. Use the tea towel to assist (similar to sushi rolling).
There are two ways to cook this. For separate knishes, pull off 1 inch sections and tuck / pinch the dough on the ends together. Or bake as is in the roll, to be cut later after baking.
Place on a buttered cookie sheet, seam side down. Brush with an egg wash if you want these to be shiny, and bake in a preheated 375* oven for 20-25 minutes.