Spinach-and-Cheese Pie

Heat the vegetable oil in a large skillet over medium heat. Add the onion and sauté until softened — 5 to 7 minutes. Add the spinach and cook until all of the liquid has evaporated and the mixture is dry — about 5 minutes. Remove skillet from heat and let the mixture cool to room temperature. Heat oven to 350 degrees F. Grease a baking sheet (preferably a dark nonstick one) and set aside. In a large bowl, combine feta, Parmesan, and ricotta cheeses. Stir in the eggs, parsley, oregano, and nutmeg. Add onion-spinach mixture and combine. Set filling aside. Place the thawed phyllo sheets between 2 pieces of waxed paper, then cover the waxed paper with a clean damp kitchen towel. (Since phyllo dough dries out very quickly, be sure to replace the damp towel each time you remove a sheet of phyllo and try to work as quickly as possible.) Remove one phyllo sheet and lay it on a work surface. Brush sheet with olive oil and sprinkle lightly with bread crumbs. Repeat with 8 more sheets, placing each new one at an angle, like the petals of a flower, to form a circle. Spoon the reserved filling into center of dough and pull corners up around filling. Brush remaining 4 sheets of dough with olive oil and layer over pie; tuck edges underneath to seal. Using a large spatula, transfer pie to prepared baking sheet. Brush top with oil and bake until filling feels firm to the touch and dough is golden brown — 45 to 55 minutes. Transfer to a wire rack and let stand at room temperature for at least 15 minutes before serving.