# Dice the
onions, roast them with 1/3 cup vegetable oil.
# When the
onions soften a little bit, add finely sliced
peppers in it. When the
peppers start to turn to yellow add the diced
liver of calf.
# Cook it over medium heat for 40 minutes. Remove it from the stove, when it cools down, sprinkle salt and black
pepper on it and stir. By this way the filling will be ready.
# Lay the yufkas onto the bench. Cut each yufka into 8 triangles. You get 32 triangles by this way.
# Each borek is prepared with 2 triangles. Spread the mixture of
milk, egg white and 1/6 cup vegetable oil all over the first triangle.
# Place the large side of the triangle into a small bowl or cup, the edges should be outside of the bowl. Spread the same mixture all over the second triangle, place its larger side onto the triangle which is standing in the bowl, its edges should be out of the bowl also.
# Put the drained filling which includes the
liver, onto the triangles which are standing in the bowl and then close the edges of the triangles which are staying out of the bowl onto the filling. And reverse the bowl onto the greased oven tray to place the borek on the tray.
# Prepare all the bowl shaped boreks by this way (16 boreks total). Spread the remaining yolk all over.
# Place the tray into the oven which is preheated to 374 F Bake them until they turn to red.
# Serve them warm.