In a large bowl, combine the all-purpose flour and 1/2 teaspoon salt. Make a well in the center and stir in the Greek yogurt and 1/2 cup water until a rough dough forms; add more water, 1 tablespoon at a time, only if needed.
Turn the dough onto a lightly floured surface and knead about 3 minutes until smooth and elastic. Cover with plastic wrap or a clean towel and let rest for 10 minutes.
Heat 1 tablespoon olive oil in a medium skillet over medium heat. Add the chopped onion and minced garlic and sauté 3–4 minutes until softened.
Add the ground lamb to the skillet, breaking it up with a spoon, and cook 4–5 minutes until browned. Stir in the tomato paste, ground coriander, smoked paprika, ground cumin, 1/2 teaspoon salt and 1/4 teaspoon pepper.
Add the thawed, squeezed-dry chopped spinach to the meat mixture, stir and cook another 1–2 minutes. Remove from heat and let the filling cool slightly.
Divide the rested dough into 4 equal portions. On a floured surface roll each piece into a rectangle about 12 by 10 inches.
Spoon about 3 tablespoons of the lamb and spinach filling into the center of each dough rectangle. Top each with chopped mint, chopped green onions, chopped parsley, 1/4 cup crumbled feta (each), and some chopped tomato.
Fold the dough edges over the filling to seal, forming a flat parcel. Repeat with remaining pieces.
Heat a 12-inch cast iron (or large nonstick) skillet over medium and lightly spray or oil. Cook 1–2 gozleme at a time (depending on pan size) for 3–4 minutes per side until golden brown and crisp, adding more spray as needed.
Cut each gozleme in half diagonally and serve warm with lemon wedges and olives.