Preheat the oven to 375 degrees F.

Heat the olive oil in a medium saute pan, add the onion, and cook for 5 minutes over medium-low heat. Add the scallions, and cook for another 2 minutes until the scallions are wilted but still green. Meanwhile, gently squeeze most of the water out of the spinach and place it in a large bowl.

When the onion and scallions are done, add them to the spinach. Mix in the eggs, Parmesan cheese, 3 tablespoons bread crumbs, the nutmeg, salt, and pepper. Gently fold in the feta and pine nuts.

Place 1 sheet of phyllo dough flat on a work surface with the long end in front of you. Brush the dough lightly with butter and sprinkle it with a teaspoon of bread crumbs. Working quickly, slide another sheet of phyllo dough on top of the first, brush it with butter, and sprinkle lightly with bread crumbs. (Use just enough bread crumbs so the layers of phyllo don't stick together.) Pile 4 layers total on top of each other this way, brushing each with butter and sprinkling with bread crumbs. Cut the sheets of phyllo in half lengthwise. Place 1/3 cup spinach filling on the shorter end and roll the phyllo up diagonally as if folding a flag. Then fold the triangle of phyllo over straight and then diagonally again. Continue folding first diagonally and then straight until you reach the end of the sheet. The filling should be totally enclosed. Continue assembling phyllo layers and folding the filling until all of the filling is used. Place on a sheet pan, seam sides down. Brush with melted butter, sprinkle with flaked salt, and bake for 30 to 35 minutes, until the phyllo is browned and crisp. Serve hot.