Roll out the puff pastry to a 12-inch (27.5-cm) square about ⅛ inch (3 mm) thick (see Note). Prick the dough lightly.
Place the dough on a sheet of cardboard or an inverted sheet pan. Brush with egg wash.
Using the back of a chef’s knife, mark a diamond pattern in the egg wash.
Refrigerate or freeze the dough until firm. The egg wash will dry slightly. It is much easier to brush on the egg wash and mark the dough before you cut it than to try to do each fleuron individually.
Starting from the bottom edge of the square on the left side, cut away a little less than a half-circle of dough using a 3-inch (7.5-cm) fluted cookie cutter dipped occasionally in oil. Cut straight down and do not twist the cutter. Make a second cut parallel to the first and 1½ inches (3.7 cm) higher to form a crescent (Figure 2-14). The cut that makes the top of one crescent becomes the bottom of the next. Continue cutting until you have made the first row of 7 fleurons. Cut 3 more rows of 7 fleurons each in the same way. The only scraps of dough will be at the beginning and at the end of each row. Place the individual pieces on a sheet pan lined with baking paper.
Bake at 400°F(205°C) for about 10 minutes or until golden brown and baked through. You may need to lower the heat and leave the fleurons in a few minutes longer to finish drying (Figure 2-15). Fleurons can be frozen before baking; bake directly from the freezer for about 12 minutes following the same procedure.