To make the dough, place the flour, salt, olive oil in a bowl. Add about 1/2 the water and stir to hydrate the flour, adding more water as needed, just until it comes together into a cohesive dough. It should not be overly sticky.
Place onto a lightly floured surface, and knead for a few minutes until smooth. Cover with plastic wrap and leave for 30 minutes.
In a large bowl, add the spinach or kale leaves, onion, lemon juice and season with a pinch each of sea salt and black pepper. Add the feta and massage it into the leaves and onion, combining well. Taste and make sure you’re happy with the seasoning.
Divide the dough into 4 equal pieces. On a lightly floured surface, roll the dough out into an 7 to 8 inch circle (bigger or smaller is okay too). Place a big mound of the filling onto one side, and fold the dough over, pressing it to form a semi circle (no need to seal). Repeat with the remaining dough.
Heat a medium or large skillet (frying pan) on medium high heat. When hot, drizzle with olive oil, and carefully place a gozleme onto the hot surface, using a flexible spatula to press it onto the hot surface to encourage charring. Cook for 3 to 4 minutes until charred, and then flip it over and cook for another 3 to 4 minutes until the their side is cooked, with charred spots. Cook remaining gozleme.
Cut into wedges, squeeze over some lemon juice and eat immediately.