The flaky, golden pastry in this strudel is phyllo dough, a paper-thin Greek pastry. To keep the sheets moist as you’re working with them, cover the unbuttered stack with plastic wrap. Slashing the top of the strudel before baking allows steam to escape and ensures a crisp result.
Top each sheet of margarine-or butter-coated phyllo with another sheet of pastry (cover unused phyllo with plastic wrap until needed). Brush each sheet with margarine or butter.
Fold the short sides over 1 inch. Roll the dough around the filling from one long side like a jelly roll.
Set the roll on a baking sheet, brush with margarine or butter, and sprinkle with cheese. Slash the top 5 to 7 times at even intervals.