Make the Dough: In a large bowl, stir together flour, salt, warm water, and cold milk using a wooden spoon until the dough comes together and there are no dry bits. Turn it out onto a floured surface and knead until springy, about 5–8 minutes. Cover and let rest for 30 minutes to 1 hour.
Prepare the Filling While Dough Rests: In another bowl, mix spinach, onion, scallions, parsley, dill, paprika, cumin, salt, pepper, and optional pepper flakes. Toss, then massage the mixture with your hands to soften the greens. Fold in the feta and set aside.
Divide & Shape Dough: Lightly flour your work surface. Cut the rested dough into 8 equal pieces (about ⅓ cup each). Gently shape each into a ball, place seam-side down, and let rest for another 15 to 30 minutes.
Preheat & Prep Baking Sheets: Preheat your oven to 200°F and line two rimmed baking sheets with parchment. Keep them near your stovetop for later use.
Roll & Fill: One piece at a time, roll the dough into a 10-inch round. If it resists, let it rest and try again. Place 2 to 3 tablespoons of filling on one half, sprinkle with ¼ cup mozzarella, then fold over and seal the edges.
Cook the Gözleme: Heat a skillet over medium until water droplets sizzle and evaporate. Lightly brush the pan with olive oil, then cook 1 or 2 gözleme at a time, pressing occasionally to prevent puffing. After about 2 minutes, brush the tops with more oil, flip, and cook 2 more minutes. Flip again for another 1 to 2 minutes until golden and fully cooked.
Keep Warm & Serve: Transfer cooked gözleme to the preheated oven while you continue frying the rest. Serve hot.