01 - In a large bowl, combine the flour and salt. Add the lukewarm water and olive oil, stirring until a rough dough forms. Turn out onto a lightly floured surface and knead for 5-7 minutes until smooth and elastic. Cover with a damp cloth and let rest for 20 minutes.
02 - Heat 1 tablespoon olive oil in a skillet over medium heat. Sauté the onion until softened, about 2-3 minutes. Add the chopped spinach and cook until wilted. Remove from heat and let cool slightly. Stir in the crumbled feta, black pepper, and red pepper flakes. Mix thoroughly to combine.
03 - Divide the rested dough into 4 equal portions. Roll each piece on a floured surface into a thin oval or rectangle, approximately 1/8 inch thick.
04 - Place one quarter of the spinach and feta filling on one half of each rolled dough piece, leaving a small border around the edges. Fold the dough over the filling to enclose it and press the edges firmly to seal.
05 - Heat a large skillet or griddle over medium heat. Brush each gözleme lightly with olive oil or melted butter. Cook for 2-3 minutes per side until golden brown and crisp.
06 - Remove from the pan, slice into portions, and serve immediately while hot.