Remove dough from refrigerator and turn on a floured board. Roll the dough out to about 1/8 inch thick.
Fold dough in half and transfer to a baking sheet lined with parchment paper or a baking mat.
Lay apples in rows one slice slightly on top of the other in the center of the dough leaving 2-3 inch border. You can also slowly pour apple filling into the center of the dough.
Carefully fold the edges over the filling. Brush crust with egg white.
Bake galette for 35 - 40 minutes or until golden brown.
Remove from oven and allow to cool for five minutes.
Serve with vanilla ice cream or whipped cream.