Preheat your oven to 375
Make sure your pie-dough is still cold, but not frozen. It's best to allow your frozen pie-dough to thaw out in your fridge overnight. But if you haven't done that - you can always just let your dough sit out on your counter for an hour or two and let it thaw out a little. But you still want your pie-dough to be COLD.
Once your pie-dough has thawed slightly, it's time to roll it out.
On a lightly flowered surface, using a rolling pin, roll your pie dough out into a circle until the dough is between 1/4-1/2 inch thick (my dough formed roughly a 12" circle). It doesn't have to be a perfect circle.
Then transfer the dough to a baking sheet lined with parchment paper
Meanwhile, prepare the filling by adding the blueberries, lemon juice/zest, sugar, salt, and corn starch to a bowl. Give it a gentle toss.
Then add the filling to the center of the dough and spread it out, leaving a good 1-inch border along the circle.
Fold the border of the dough up and over the berries and use your fingers to gently "fold and crimp" the dough. Again, it doesn't have to be perfect.
Then using a pastry brush or a spoon, lightly brush milk on the edges of the galette and sprinkle with the finishing sugar.
Place the baking sheet into the oven and bake for 25-30 minutes or until the galette is golden brown and bubbly.
Remove from the oven and allow the blueberry galette to cool slightly.
To serve, garnish with additional lemon zest and a generous scoop of ice cream
Enjoy!