Yukon Gold Potato Knishes With Osetra Caviar

Preparation

1. Step 1

   Place potatoes in a large saucepan, and cover with cold water. Bring to a boil, reduce heat and cook at barest simmer until a skewer glides easily through potatoes, about 1 hour. Drain potatoes, cool slightly and peel. Run potatoes through a food mill and into a bowl. Grate onion on the large holes of a box grater directly into bowl with potatoes. Season with plenty of salt and some pepper. Stir in ½ cup creme fraiche. Cool to room temperature. (Potatoes can be covered and refrigerated for up to 1 day.)

2. Step 2

   Set one wrapper on a work surface with one corner facing you. Spread scant ¼ cup potatoes about 2 inches above bottom corner so that potatoes form 1-inch-wide strip that extends almost from one side of wrapper to the other. Fold bottom corner of wrapper over potatoes. Roll wrapper, folding in sides to enclose potatoes. When you get three-quarters of the way to the top, brush remaining edges with beaten egg and continue rolling to seal. Repeat with the rest of the wrappers and filling. (Knishes can be refrigerated, uncovered, for up to 1 day.)

3. Step 3

   Heat 1 inch oil in a large, deep saucepan until very hot but not quite smoking, about 375 degrees. With tongs, add several knishes, and fry, turning once or twice, until golden brown all over, about 1 minute. Remove from oil, and drain on paper towels. Fry remaining knishes in batches.

4. Step 4

   With serrated knife, trim a thin slice from either end of each knish. Cut each knish crosswise into three pieces. Arrange pieces, with one cut side up, on a platter. Top each piece with a dollop of remaining creme fraiche and a little caviar. Serve immediately.