In a bowl, pour half the milk and heat it well. Put the yeast, sugar and 1 tbsp flour in it. Stir and leave the yeast to bubble. It needs to triple in volume.
In the meantime, sift the flour. Make a well in it. Beat the eggs with the rest of the products and add the effervescent yeast to it. Knead a soft, nonstick dough and leave it to rise.
Once risen, divide it into 3 balls. Roll out each ball into a round sheet and pour some melted butter over it. Place the 2nd sheet on top, after rolling it out as well. Put butter again and the 3rd rolled out sheet.
Once you've placed all 3 sheets on top of each other, wrap the whole thing into a roll and knead it a little to make it a little longer. Then cut out triangles from 1 sheet but leave the 2 ends of the roll for the middle of the pita.
Leave it to rise again. Smear it with egg yolk. Bake in a preheated 374°F (190 °C) oven.