What is the trick of kol pastry?

The tips of kol pastry are as follows:

The dough is soft: A soft dough should be obtained by adding the flour in a controlled manner.
Opening the glands: The meringues should be greased with a mixture of butter and oil and rolled out by hand instead of a rolling pin.
fine opening: The meringues should be rolled out as thinly as possible.
hold: The pastry may lose its crispness if kept for too long, so it should be cooked just before serving.
inner mortar: The stuffing can be prepared with different ingredients such as minced meat, spinach or cheese.
Resting before cooking: In order for the pastry to be more crispy, it is recommended to rest it for at least 15 minutes before cooking.
Using butter: Butter makes the pastry crispy.
Addition of vinegar: Vinegar added to the dough contributes to the crispiness of the pastry.