In a food processor with a pastry blade, pulse the flour, sugar and salt. Cut in the cold, unsalted butter until the ingredients form course crumbs. Gradually add the ice water, one tablespoon at a time, continuing to pulse until the course crumbs form a dough. The dough should be smooth, not sticky or runny. Shape the dough into a ball, wrap it in plastic wrap and refrigerate for at least 30 minutes.

Preheat the oven to 400 degrees F and line a baking sheet with parchment paper. Spray the parchment with olive oil spray. In a separate bowl, mix the blueberries, cinnamon, sugar and cornstarch and set aside.

On a lightly floured surface roll out the chilled pastry dough and knead it several times, adding more flour as needed. Roll out the dough into a circle that is about 1/8 inch thick. Remember, it doesn't have to be perfect—that's part of the fun of this recipe.

Transfer the dough from the lightly floured surface to the baking sheet with parchment paper. Gently add the blueberry mixture to the center of the pastry, making sure to leave a small border around the edges. Fold the edges of the dough over the filling, one side at a time.

Make an egg wash with a beaten egg and gently brush it over the top sides of the pastry dough.

Bake the galette for 40 minutes, or until the crust is golden brown and the filling is bubbling.

When the pastry has finished baking in the oven, gently transfer the galette on the parchment paper from the baking sheet to a cooling rack. Let the galette cool for about 10 minutes before serving and savoring.

Savor the simplicity of this Rustic Blueberry Galette!