Read my many posts on fatayer dough and how to shape for success. We want a sticky dough, not too risen, rolled thin. Pinch like crazy when shaping the seams and again just before baking. Enjoy the beauty and the absolutely divine flavor of the feta and kale filling.
Proof the yeast by dissolving it in ¼ cup of the warm water with the sugar or honey. Set aside for about 10 minutes, or until the mixture looks frothy and creamy. If using instant yeast, skip this step and add the yeast to the flour in the next step.
Whisk together the flour and salt in a mixer bowl or medium bowl. Create a well in the center and add the oil and proofed yeast mixture. Using a stand mixer fitted with the hook attachment or by hand, slowly work the wet ingredients into the dry, adding 1/2 cup of the water slowly. Add more of the water only as necessary until the dough comes together and is cohesive.
Knead the dough by hand or with the dough hook in the mixer until the dough is very soft, smooth, and tacky/sticky to the touch (but it should not leave dough on your fingers). Kneading by hand can be awkward at first because the dough is so wet, but as you knead, the dough will firm up a bit and absorb all of the water.
In a clean bowl at least twice the size of the dough, lightly coat the dough and the sides of the bowl with oil. Cover the bowl (not the dough) with plastic wrap and set the dough aside to rise in a warm spot until doubled, one hour and not more than 90 minutes. Take care not to overproof the dough.
While the dough rises make the filing. In a medium bowl, stir the kale, feta, scallion, mint and sumac until well combined.
Heat the oven to 375°F. Line two heavy baking sheets with parchment paper or foil.
Roll half of the dough out on a dry work surface to 1/8-inch thickness (see how here). Gently lift the dough from the edges to allow for contraction. Cut dough into 4-inch rounds. Knead together the scraps, cover with plastic, and set aside.
Fill the rounds of dough by placing a heaping tablespoon of filling in the center of each round. Be careful not to let the filling touch the edges of the dough where it will be gathered together and closed. A good way to keep the filling in the center is to lower the spoon with the filling over the center of the dough (parallel to it) and use your fingers to slide the filling off the spoon and into the center of the dough circle. Be sure to wipe your fingers off before shaping to avoid kale specks on the dough.
Bring three sides of the dough together in the center over the filling and pinch into a triangle. Close the dough firmly.
Place the fatayar on the baking sheets and generously brush or spray the dough with olive oil. Bake in the middle of the oven for 18-20 minutes, or until golden brown. Set the oven on convection bake for the last 5 minutes, or place under the broiler, to encourage browning if needed.
Repeat the process with the other half of the dough, then with the scraps that have been kneaded together and left to rest for a few minutes before rolling out.