Start by making the filling. Heat 1/2 cup olive oil in a deep skillet and sauté the onion, leeks, and green onions for several minutes until softened. Add the spinach a little at a time, letting it wilt and cook off its liquid. Season with salt, taste, and adjust as needed.

Remove the skillet from the heat. Once the filling has cooled, add the dill, mint, pepper, and eggs. Mix well.

Add the feta cheese and mix again.

Brush a medium baking pan with olive oil. Layer half the phyllo sheets in the pan, brushing each with olive oil. Spread half the filling over the phyllo, then place another sheet on top. Add the remaining filling and finish with the rest of the phyllo sheets, brushing each with olive oil. Let the first sheets hang over the edge of the pan; after adding the filling, fold them in to seal the pie.

Score the pie into pieces with a sharp knife and brush the top with olive oil. Sprinkle with water and bake in a preheated oven at 350°F (180°C) for 50-60 minutes.