Preheat the oven to 350 F (180 C).
Prepare two cookie sheets by lining them with parchment paper. Set aside.
Put all the ingredients, except the egg for glazing and the fleur de sel, in the bowl of the food processor fitted with the steel blade.
Pulse until the dough forms and comes together in a ball.
Remove the dough from the food processor, wrap it in plastic wrap, and refrigerate for 30 minutes.
Remove the dough from the refrigerator and roll it out on a floured surface to a thickness of 1/4 inch (5 mm).
If you have a stamp, mark your dough, then cut out with a cookie cutter of the same diameter.
Repeat the same steps with the leftover dough.
Place the rounds of dough on the prepared cookie sheets and reserve in the freezer for 10 minutes.
Remove the cookie sheets from the freezer and brush the cookies with the beaten egg.
Sprinkle with fleur de sel.
Bake for 15 minutes or until the cookies are lightly golden.
Remove from the oven and let cool on a rack until completely cooled.