First knead the dough made from the flour, salt water and a pinch of salt. Roll out a rectangular shape from the dough and coat it with half of the butter or margarine. Roll out the dough by forming a cube and leave it in the freezer for 20 minutes to harden. Roll out the dough into a rectangular shape 1 cm thick. Apply the other half of the margarine or butter and fold the dough back into a cube. Leave for 20 minutes in the freezer to rest. Roll out the dough into a rectangular shape and mark 1 cm on each side with a knife (do not cut the dough, but just mark it). Coat the inside of the puff pastry with apricot jam, then arrange the halves of the apricots with the cut part bottom faced. Coat the ends with the whipped yolk and milk and sprinkle with sugar in that part for a tastier crispy crust. Bake the pie in a preheated oven at 190 degrees for about 20 minutes.