Spanokopita ( Spinach Pie)

Preheat the oven to 350 degrees F.Heat the oil in a large pan, saute the spinach, the scallions and the parsley until the spinach wilts, tossing it frequently. Remove the leafy vegetables, squeeze out excess liquid. Transfer the mixture into a large bowl and allow it to cool.Add feta, salt and pepper to the spinach. Unroll the phyllo dough on a flat surface and keep it covered with waxed paper and a damp towel so it doesn't dry out. Using a sharp knife, cut the dough into sheets to match the size of your large casserole dish and recover with the towel. Butter a large casserole dish and spread 6 sheets of phyllo, brushing each with butter, on the bottom of the dish. Spoon the spinach filling over the phyllo, then cover with 6 more sheets of phyllo, buttering each sheet. Score the top 3 sheets with a sharp knife. Bake 40 to 45 minutes, or until top is golden. Let stand 15 minutes, then cut into squares and serve warm.