There are many versions of this standard pastry wrapped mashed potato entrée. This is pretty traditional and as good as any knishes off a New York street vendor. If your kids or anyone else doesn’t like onions or a pronounced onion taste, omit the sautéed onions and use the onion powder called for. This makes tons of little knishes or about 2 dozen hefty, grandma styled knishes. If you were really busy, you could even use boxed mashed potatoes for a shortcut and still have amazing knishes. You can also use storebought puff pastry or Sour Cream Mock Puff Pastry.