Put the flour and salt in the bowl of a KitchenAid fitted with the dough hook

mix the water and oil, pour in the bowl, and start the KitchenAid

once the dough comes together let it knead the dough for about 2 minutes, KitchenAid says this is equivalent to 10-12 minutes of kneading

when the dough is done, wrap it up and put it in the fridge to chill

while it chills make the filling, begin with cooking the frozen spinach, either in the microwave or on the stovetop

Once it's cooked, drain it in a colander, cool completely, THEN squeeze out every remaining drop of liquid

mix the spinach with the feta, parmesan, walnuts, lemon zest, and the nutmeg

set aside to chill until ready to use

when the dough is done resting

melt the butter in a saucepan and set aside

lay clean towels on a long work surface, sprinkle with corn starch

divide the dough into 5 pieces

run a piece through the KitchenAid pasta roller on the number one setting, continue rolling the dough through the machine moving up through the numbers until you hit five

move the dough to the prepared towel, use the backs of your hands to gently stretch the dough as wide as possible

brush with melted butter, cover while you work on the next piece

repeat with all five pieces

lay the filling down one long edge, fold over each end to keep the filling from leaking out

roll the filo over to form a long snake, then coil around to make a flat circle

slide on a greased baking sheet OR in a springform pan

mixing any remaining melted butter with the egg yolk and brush over the top of the pie, sprinkle with the chopped walnut

bake 350˚ for 35-45 minutes, or until the filo is flaky, and it's baked through

cool slightly, slice, and serve