Tiropites can be assembled in advance, frozen, and baked just before serving.
Stem, wash well, and coarsely chop:
      2 pounds spinach, or 3 10-ounce bags spinach
Heat in a large skillet over medium heat:
      2 tablespoons olive oil
Add and cook until softened, 5 to 7 minutes:
      1 large onion, finely chopped
      4 scallions, finely chopped
Add the chopped spinach a handful at a time. Cook until the spinach is wilted and the liquid is released, 5 minutes. Increase the heat to high and cook, stirring often, until the liquid has evaporated and the spinach is dry, 7 to 10 minutes. Stir in:
      1/4 cup snipped fresh dill or chopped fresh parsley
Let stand until cool enough to handle, then squeeze to remove the excess liquid. In a medium bowl, lightly beat:
      4 large eggs
Add the cooked spinach mixture along with:
      8 ounces feta cheese, crumbled
      2 tablespoons grated kefalotiri cheese (Greek grating cheese) or grated Parmesan cheese
      1/2 teaspoon salt
      Several grinds of black pepper
      Pinch of freshly grated nutmeg or ground nutmeg
Lightly oil a 13 x 9-inch baking pan. Melt:
      8 tablespoons butter
Unroll on a dry work surface:
      1 pound phyllo dough, thawed if frozen
Preheat the oven to 375°F. Trim 1 inch from the edges of the phyllo dough. Cover with a dry towel and cover the dry towel with a damp towel. Brush 1 sheet of phyllo with melted butter. Place another sheet on top of the first and brush with butter. Cut lengthwise into 3-inch-wide strips. Put a heaping tablespoon of filling at one end about 1 inch from the edge and fold the corner over it to make a triangle. Continue to fold, as you would a flag, until the whole strip is folded into a triangular packet. Brush with melted butter. Repeat with the remaining filling and phyllo. Bake the tiropites on a baking sheet until golden brown, 15 to 20 minutes. Tiropites can be assembled in advance, frozen, and baked at  375°F for 15 to 20 minutes just before serving.