Spanakopita (Courtesy of The Moosewood Cookbook)
Yields: About 8 servings
Filling:
1 Tbs olive oil (I used 2)
2 cups minced onion
1/4 to 1/2 tsp salt
1 tsp oregano
1 tsp basil
2.5 lbs fresh spinach, stemmed and finely chopped
5 medium cloves garlic, minced
3 Tbs flour
2 to 3 cups (packed) crumbled feta cheese (about 1 lb)
1 cup cottage or pot cheese
Black pepper, to taste
1/3 to 1/2 cup olive oil, for the filo
1 lb filo pastry leaves (approx 20 leaves) -- thoroughly defrosted 
Directions
Preheat oven to 375 F. Oil a 9 by 13 inch baking pan.
Heat 1 Tbs olive oil in a dutch oven. Add onion, salt, and herbs, and sauté for about 5 minutes, or until the onion softens. Add spinach, turn up the heat, and cook, stirring, until the spinach wilts (5 to 8 minutes). Stir in the garlic.
Sprinkle in the flour, stir, and cook over medium heat 2 to 3 more minutes. Remove from heat.
Mix in the cheeses. Taste to correct seasonings, adding lots of black pepper.
Place a sheet of filo in the oiled pan, letting the pastry edges climb up the sides. Brush lightly with oil, and add another sheet. Keep going until you have a pile of 8 oiled sheets. Add half the filling, spreading it to the edges, then repeat with 8 more sheets of oiled filo, followed by the remaining filling. Layer the rest of the filo over the filling, brushing oil in between. Oil the top, tuck in the edges, and bake uncovered for about 45 minutes or until golden and crispy. Cut into squares and serve hot or warm. {Note: After making this recipe several times, I think the best results were obtained when the pie was baked for 30 minutes COVERED and then an addition 5 minutes UNCOVERED.  The filling was much creamier and the top was not quite as dark. I recommend doing it this way.}