Preheat oven to 350°F. In a large skillet on medium heat, add the olive oil and spinach. Let it wilt completely, and then place it in a large bowl and set aside to cool. Once cooled, tightly squeeze all the excess water from the spinach and discard the liquid. The drained spinach should be about the size of a softball. Chop the spinach evenly so no long stems remain. Place back into the empty bowl.
In the same skillet, add a little more olive oil, and the chopped leek and onion. Sauté for 5 minutes. Add the garlic and spring onions, stirring frequently so not to burn the garlic for another 4 minutes. Add the wine and let it reduce by a little more than half, stirring frequently. Add the mixture to the bowl with the spinach.
In a separate bowl, whisk egg, egg yolk, salt and pepper, then add to the spinach bowl. Add feta parmesan, herbs, lemon juice, zest, salt and pepper. Mix well until everything is even.
Brush the bottom and sides of an 8" springform pan with the melted butter. Brush one phyllo sheet with butter and place on the bottom of the pan. Tuck the sides around the bottom edge. Continue to brush each phyllo dough sheet with butter and place half on the inside of the pan, form it to the edge and side, then let the rest hang over the outer edge of the pan. Turn the pan slightly and repeat with the remaining phyllo sheets all the way around the pan. I used about 15-18 phyllo sheets. Make sure there aren't gaps on the bottom, inside edge and sides of the pan.
Add the spinach mixture and spread evenly. Fold the outer phyllo dough inside top edge of pan creating light folds for texture as it cooks.
Bake on center rack for 50 minutes, or until the dough is golden brown. Let it cool in pan for at least 30 minutes. Unlock and carefully lift the springform pan side away and serve.