In a medium-sized bowl mix the flour, with the salt, vinegar, water and olive oil.
Knead the dough for at least 5 minutes. You should have a dough soft and sticky. Without leaving any fragments on your hands though. If not, dust in a bit more flour or water as needed.
Set aside and let it rest for 15-20 minutes, covered with a dampened tea towel.
Mix the olive oil, with the sunflower oil that is for greasing the phyllo, in a small bowl and keep it next to you. Divide the dough into 4 equal parts.
Dust your working surface with flour. Take the first dough piece in your hands and shape it into a ball. Then flatten the ball into a disk shape. Place it on your working surface. Dust it with plenty of flour on top.
Start rolling it open (towards one direction, up or down). Once the dough starts to feel sticky, pick it up, dust the surface with flour again, and flip the dough. Dust the dough with flour on top as well, and start rolling it again. Repeat process until you have a big enough phyllo to add to your pan.
Grease a round 9-inch baking pan, with plenty of the oil mixture. Add the first phyllo in the pan, and grease the phyllo as well.
Add another phyllo and add the filling.
Preheat oven to 220°C / 428°F.
Add 2 more phyllo layers with plenty of oil in between.
Cut off any excess phyllo that hangs out of the pan. Close the pie by turning the cut phyllo edges inwards, to create a nice pie edge.
Grease the top of the pie with the oil, and prick a few times with a knife.
Bake for about 35 minutes. Shake the pan to see if the pie is ready. If it feels sticky to the bottom bake for a few more minutes.
Let it cool down for about 30 minutes before cutting and serving.
Cut to 8 pieces and serve.