The night before, in a bowl, mix the flour, sugar, eggs, white cheese, salt, and yeast until the mixture is well combined.
Cover the bowl with plastic wrap and refrigerate overnight.

The next day:
Roll out the dough into a rectangle three times as long as it is wide.
Spread the butter over two-thirds of the dough and fold into thirds (the unbuttered part in the middle, then the last third on top).
Turn the dough a quarter turn and roll out again.
Repeat the operation three times.

Roll out the dough on a floured work surface into a large rectangle of 36″ x 26″ x 1/4″ (70cm x 61cm x 0.5cm).
Cut the dough into 16 rectangles of equal size.
Place a chocolate bar at the edge of each rectangle and roll the dough around it, without tightening too much.
Place the chocolatines on two baking sheets lined with silicone mats or parchment paper, making sure to position the fold of the dough underneath the chocolatines.

Glaze with a little bit of egg beaten with a little milk and let rise at room temperature for about 2 hours.

Preheat the oven to 350°F (180°C).
Glaze a second time and bake the chocolatines for 20 minutes or until the top is golden brown.
Let cool on a rack.