An excellent version of a Greek favorite from my friend, Gloria.
Heat olive oil in a medium pan and cook diced onions till tender.
Add spinach and stir till heated through.
Mix together the feta cheese, ricotta, Jack cheese, eggs, parsley if desired, breadcrumbs and salt and pepper to taste. Add to onion/spinach mixture.
Grease a 9x13inch baking dish. Spread 1/2 of the dough, 2 sheets at a time buttering every second sheet into the pan. Repeat until one half of the package is used. Spread the spinach mixture evenly over the phyllo. Repeat procedure until all the phyllo is used up. Butter the top well. Cut with a fine sharp-edged knife into desired pieces (It's easier to do this now rather than after baking). Bake in a 350 degree oven until golden. You may need to put a cookie sheet or other flat sheet under the pan as the dish may sometimes overflow.
Gloria has also used small frozen phyllo "cups" in the freezer section of the grocery store, for individual servings.
1/4 cup olive oil
1 medium onion, diced
2 10oz. bags frozen chopped spinach, thawed and squeezed dry
8 oz. feta cheese, crumbled
12 oz. ricotta
8 oz. grated Jack cheese
3 eggs beaten
1/4 cup minced fresh parsley (optional)
1/4 cup plain bread crumbs
Salt and pepper to taste
1 pound phyllo sheets (cut in half-width)
1/2 pound butter (2 sticks)