Put dough in the refrigerator overnight and leave at room temperature at least 1/2 hour before using. Drain spinach in colander, squeeze out extra moisture. I use a 13 x 9 inch pan since the dough sheets are larger you can use a larger pan. Butter bottom of pan.
Have all other ingredients on hand and ready. Mix the spinach with the cheese which can be crumbled with a fork. Add salt and pepper and a few drops of oil along with a beaten egg. Mix well. Unfold the dough, gently. Have a damp cloth or tea towel handy and cover as soon as a layer of dough is removed. Brush dough lightly with butter (best to use a pastry brush). If using a 13 x 9 inch pan fold the sheet under itself but be sure to cover the pan. Layer in this manner, alternating the folded sheets for 6 layers. Be sure to brush a dab of butter on each sheet. Cover any exposed corners with butter.
Add 1/2 spinach and layer for another 4 to 5 sheets. Add remaining spinach and add 6 layers on top. Make sure the top layer is not torn or damaged. When finished cut with knife lengthwise through the top half of pie.
Bake at 350 to 375 degrees for about 45 minutes to 1 hour until top is golden brown. DO NOT COVER WITH ALUMINUM FOIL - it will make the dough soggy. Cover lightly with wax paper. Reheat uncovered so the top crust will remain crispy and DON'T microwave it!
This can be made up (don't bake) and frozen successfully. Remove, thaw and cook.
