While many cooks prefer thicker homemade phyllo for savory pies, frozen commercial dough, which is readily available in supermarkets, can be substituted. Examine frozen dough before using, though: You can’t tell from the package, for example, how long the dough has been in the freezer, if moisture has gotten inside the package, causing the sheets to stick together, or if air has entered and turned the pastry brittle.
At home, frozen phyllo should be defrosted unopened in the refrigerator overnight, then allowed to sit (still unopened) at room temperature for two hours. If phyllo thaws too quickly, or if the sheets are cold when you unfold them, they will crack along the folds or stick together at the corners. Thawed phyllo sheets will dry out quickly, especially in a hot kitchen; always keep the unfolded pastry between two dry towels while working with it. If substituting commercial phyllo, use four sheets for every one of homemade, and bake according to package instructions until golden brown.