# Prepare the filling with 
mushroom at first. Slice the 
onion into circles, Put 4 tbsp vegetable oil into a small pot.
# Add 
onion circles into it, when the 
onion gets particularly cooked add finely sliced green 
onion, long green 
pepper and pounded 
garlic cloves in it.
# Just before the ingredients get cooked add washed, drained, and finely sliced 
mushrooms in it, sprinkle salt all over, stir and cook for 25 minutes over low heat, and then turn off the heat.
# Cut each yufka into 4 pieces. You should get 12 triangle shaped yufka pieces total.
# Lay the yufka onto the bench, spread some of the mixture which includes the egg, vegetable oil and 
milk all over.
# Put some filling onto the large side of the triangle, sprinkle kashar 
cheese all over. (Because of cooking the mixture of 
mushrooms without water addition, add the remaining water of it into the borek.) 
# Roll the triangle as a cylinder, and fix one of the ends of the cylinder, and then twist the other end around the fixed one, after twisting it totally put the ending under the borek.
# After preparing all of the boreks by this way, place them onto the greased oven tray. Spread the remaining which includes yolk all over the boreks.
# Set the heat of the turn to 365 F. Place the boreks into the oven and bake until their tops turn to red.
# Serve them hot or warm.