Knishes

Directions

1. 1
   Make the filling:
2. 2
   Peel the potatoes, cut them into chunks, and place them in a large pot, covered with cold water by about an inch.
3. 3
   Bring the water to a boil.
4. 4
   Cook the potatoes until very tender, about 15 to 20 minutes, depending on the size of the chunks.
5. 5
   Drain immediately in a colander.
6. 6
   Using a food mill with the medium blade or a ricer (do not use a food processor), work the potatoes into a smooth puree.
7. 7
   Stir in 3 teaspoons of the salt (1 tablespoon) and the pepper.
8. 8
   While the potatoes cook, fry the onions.
9. 9
   In a 12-inch skillet, heat the oil over fairly high heat.
10. 10
    When the oil is hot but not smoking, add the onions and fry over medium-high heat, stirring regularly, until the onions are well wilted, about 8 minutes.
11. 11
    Lower the heat to medium, and continue to fry, stirring only occasionally, until the onions begin to brown.
12. 12
    (This could take as long as another 20 minutes.)
13. 13
    As they cook, season the onions with the remaining 1 teaspoon salt.
14. 14
    Stir the onions into the mashed potatoes.
15. 15
    Taste, and adjust the seasoning with salt and pepper (I like mine peppery).
16. 16
    Cover and refrigerate until chilled.
17. 17
    Make the dough:
18. 18
    In the bowl of a food processor fitted with the metal blade, combine the water, oil, eggs, salt, and pepper.
19. 19
    Process briefly to mix well.
20. 20
    Add 3 cups of the flour and the baking powder.
21. 21
    Process again until the dough is smooth.
22. 22
    Flour a work surface with some of the remaining flour, and scrape the dough out onto the surface.
23. 23
    Knead the dough briefly, just a minute or so, incorporating just enough additional flour to make a very slightly sticky dough.
24. 24
    Wrap the dough in wax paper or plastic, and let it rest at room temperature for an hour before rolling it out.
25. 25
    Preheat the oven to 375 degrees.
26. 26
    Cut the dough into four pieces.
27. 27
    Roll out one piece at a time to a rectangle about 18 inches long and 8 inches wide.
28. 28
    The long side of the dough should be facing you.
29. 29
    Gather some of the potato mixture in your hand and make a long, approximately 2-inch wide roll of potato along the long side of the dough, about 2 inches from the bottom edge.
30. 30
    Bring the bottom edge of the dough over the potato roll and brush the upper edge with egg.
31. 31
    Bring the upper edge of the dough over the egg-washed edge.
32. 32
    Repeat with the remaining dough.
33. 33
    Transfer the rolls to lightly greased baking sheets, seams down.
34. 34
    Brush the logs with the beaten egg.
35. 35
    Bake until golden, about 50 minutes.
36. 36
    To serve, cut the rolls into 1- to 1 1/2-inch crosswise pieces.