Natalie's Spanakopita (Greek Spinach Pie)

(This a family recipe that is always loved!  It make a tray big enough of a large party...great with Greek salad)

7 boxes of frozen chopped spinach
1 lb chopped onion (could use more if you like)
1 1/2 cups of olive oil
3-4 bunches of dill- chopped
1 -1 1/2 lbs of Feta cheese
salt and pepper to taste
8 eggs -beaten
1-2 stick of melted butter (may need more or less)
Filo dough sheets 12-14 

Drain spinach well....must be as dry as possible
Mix dill and spinach in a large bowl
Brown onions in olive oil
Combine onion with spinach mixture
Add Feta cheese, salt & pepper
Add 8 eggs beaten---mix well 

Grease a shallow baking pan (10X16) with butter
Line pan with 6-7 filo sheets....buttering in-between each sheet with melted butter
Add entire spinach mixture
Cover with remaining filo sheets with melted butter in between 

Bake in 375 oven for about 40 minutes

TIPS:

The best way to have the pie cut well in put it the freezer for a while until it gets stiff....then score out pieces with knife.  You can make the spinach mixture the night before (draining he spinach is messy and takes a little bit of time) but add the eggs the day you make it.