Defreeze the Puff Pastry (2 sheet). Cut each slice into two triangles.
Have one of the triangles with its long side towards you. Put about four pieces of Chocolate (100 gram) on it, and roll the pastry into a tube with the chocolate in the middle.
Reposition the roll so that the small triangle in the middle is towards you. Fold in the sides and roll it so that the folded part is in the bottom. Repeat steps two and three with the rest of the sheets and chocolate.
Line a baking tray with non-stick baking paper and place the croissants on it. With a brush, apply the Egg (1) on the pastry.
Preheat the oven to 200 degrees C (400 degrees F) and put the tray in. Bake for 15 minutes.