Use a sharp knife and cutting board to chop the spinach. Transfer the chopped spinach to a large bowl and sprinkle salt and mix it.
Use a different bowl to whisk together the eggs with feta, onions, and ½ cup of olive oil, mix it with the spinach and set aside.
Preheat the oven to 375F/190C degrees.
Brush the bottom of pie tin with olive oil ( you can use a 8 or 9” pie tin).
Open the dough package and put a two sheets at the bottom, then brush with olive oil on top.
Let some of the sheets along the long edge leaving about an 1” underneath.
Cover with the spinach mixture, then add on top two sheet of dough.
Repeat the same step this process and use up to half of the sheets.
Now covering the mixture with the same way as you did at the bottom half.
Roll the edges up and fold the bottom sheets over the top sheets.
Use olive oil to bush the top
Place it in the oven and bake until a golden brown or for 45 minutes.
Serve warm.