Mushroom Strudel

Cook shallots in butter in a large heavy skillet over medium heat, stirring, until beginning to soften, about 1 minute.

Add mushrooms, reserved soaking liquid, wine, 1/2 teaspoon salt, and 1/4 teaspoon pepper and cook, stirring occasionally, until liquid has evaporated, about 8 minutes.

Stir in parsley, then spread filling on a plate and chill, uncovered, until cold, about 10 minutes.

Preheat oven to 425°F with rack in middle.

While filling chills, put stack of phyllo sheets on a work surface and cut in half crosswise, then stack halves and cover with plastic wrap.

Remove 1 phyllo sheet from stack (keep remaining sheets covered) and arrange with a long side nearest you, then lightly brush with some duck fat.

Top with another phyllo sheet and brush with fat.

Spread about one fourth of mushroom filling in a narrow strip along edge nearest you to within 1/4 inch of each end, then roll up phyllo tightly around filling, leaving ends open.

Transfer roll, seam side down, to a baking sheet and make 3 more rolls in same manner, transferring to baking sheet.

Bake until golden brown, 12 to 14 minutes.

Cool slightly on baking sheet on a rack, then brush length of each roll with a very thin line of truffle oil (if using) with tip of a cotton swab.

Gently cut each roll crosswise into 8 pieces with serrated knife.

Serve strudel warm or at room temperature.