These mushroom feta borekas are a little more involved recipe but so worth it. The dough is made from scractched and filled with a sauteed mushroom base.
Combine the flour, salt and vinegar in a bowl of your stand mixer fitted with a paddle attachment. Mix on low while drizzling in the seltzer water. Keep mixing until the dough begins to pull away from the sides of the mixer - approximately 2 minutes.
Flour a work surface and knead the dough until smooth. Cover with a clean towel and rest for 30 minutes.
Using a rolling pin, roll the dough out to a thickness of about 1/4" in a rectangular shape. Spread half the butter evenly over the middle third of the dough. Fold the outer third of each side over the butter and folding the second third over the first third. Fold the top and bottom over the thirds almost forming a square. (The recipe calls for refrigerating overnight. I did not plan ahead and did it in an afternoon). Wrap in plastic wrap and place in the fridge.
Pull the dough out of the fridge and repeat the butter and folding process. (It again called for refrigerating overnight). I did a good 3 hours or so of refrigeration between the two steps.
The final step is rolling the dough out again and getting it ready for the filling. It is best to work with it cold.
Heat the oil on medium heat in a skillet. Add the onions and cook for 3 - 4 minutes until softened. Add the mushrooms and cook until browned and the water is cooked out of them - 3 - 4 minutes. Add the garlic and cook for 1 minute. Finish by mixing in the feta. Let the mixture cool.
Take your dough and cut out in 4 - 5" rounds. Place a scoop of the filling on one side of the dough and fold the dough over. Pinch with the ends with a fork to seal. Brush the top with the egg wash. Top with the poppy seeds. Repeat until all the borekas are formed. Place in a 425 degree oven and bake for 15 - 20 minutes. You want to get a nice browning.
Serve and enjoy!