Heat the olive oil in a large, heavy skillet over medium heat.
Add the sliced onion and a generous pinch of salt.
Cook, stirring often, for about 10 minutes until the onions are soft, sweet, and golden. 2.
Add the minced garlic and cook for another 30-60 seconds until fragrant.
Stir in the chopped greens, combining them well with the onions until they are wilted. 3.
Stir in the fresh herbs and za’atar, and season to taste with salt and pepper. 4. Gently fold in the chickpeas.
Taste the filling one last time and adjust seasonings if needed. 5. To assemble, spread the filling over your galette dough, leaving a 2-inch border.
Sprinkle the crumbled feta cheese evenly over the top before folding the pastry edges in.