Sift the flour into a bowl, make a hole in the middle and add the egg, oil, vinegar and salt, knead, gradually adding warm water, until you get an elastic and non-sticky dough.
The obtained dough is spread in a thin and round sheet, greased with butter at room temperature, cut the sheet into 8 equal circle segments, leaving the middle uncut.
Each segment turns over the circle in the middle of the sheet, gluing it, the order turns and is done successively only from opposite positions, face to face.
Cover the coca and refrigerate for 2 hours.
Spread with the successor a sheet that we fold in 3 lengthwise and then again width in 3.
It spreads again in a thin rectangular sheet.
Cut the sheet in 2 lengthwise then cut each side into triangles.
On each triangle we put 1 square of chocolate.
Roll from the base to the top, place them in the pan and grease them with the galenus mixed with milk.