In a bowl, combine flour, sugar, and salt.
In a small saucepan, warm the milk and dissolve the yeast.
Pour the yeast mixture into the flour mixture and knead until smooth.
Let the dough rise for 1 hour until doubled in size.
Roll out the butter between parchment paper to form a rectangle.
Roll out the dough into a larger rectangle and place the butter in the center.
Fold the dough over the butter, sealing the edges well.
Roll out the dough again and perform a series of folds (three folds).
Chill the dough for 30 minutes after each fold.
Roll out the dough to a thickness of about 1/4 inch and cut into rectangles.
Place a piece of chocolate on each rectangle and roll them up tightly.
Brush with egg wash and let rise for another 30 minutes.
Bake in a preheated oven at 200°C (400°F) for 15-20 minutes until golden brown.