Mushroom Strudel

Name: Mushroom Strudel
Ingredients: 10 g (about 1/2 ounce) dried porcini (1/2 cup; also called cèpes); 1/2 cup boiling-hot water; 1/2 pound fresh white mushrooms, trimmed and halved lengthwise; 1/4 cup finely chopped shallots (about 2 large); 2 tablespoons unsalted butter; 1/4 cup dry white wine; 2 tablespoons finely chopped flat-leaf parsley; 4 (17-by 12-inch) phyllo sheets, thawed if frozen; 2 tablespoons rendered duck or goose fat or unsalted butter, melted; Truffle oil for brushing (optional); Equipment: a wide-tooth serrated knife