Greek Spinach Pie

7-8 cups blanched spinach
1 madium onion
1/2 lb. butter
6 large eggs
2 lbs. ricotta or cottage cheese
1/2 - 1 lb. crumbled Feta cheese
salt and freshly ground pepper
1/2 lb. filo dough (thawed if frozen)

Chop spinach and dice onion. Melt 2 tablespoons butter in a large frying pan and sauté onions until soft.

Add spinach, then cook over medium-high heat until all moisture is evaporated. Remove from heat.

Melt remaining butter in a small pan. Beat eggs and stir in cheeses. Add spinach mixture; season with salt and pepper.

Gently spread the filo dough out flat and cover with a moistened towel so that the separate sheets don't dry out.

Butter a 15x10-inch baking pan 2-inch deep.

Place a sheet of dough on the bottom of the pan and brush lightly with melted butter. Continue layering sheets of dough, buttering each until there are 10 sheets.

Spread spinach mixture evenly on top and stack with another 10 sheets, buttering them as before.

Bake in a preheated oven 375°F for 15 minutes; reduce to 350°F for an additional 30 minutes. Remove from oven and allow to cool for 15 minutes before slicing.