Cover with plastic wrap and refrigerate while you are prepare the pie dough. This will allow the sugar time to draw some of the moisture out of the berries.
To assemble and bake
Preheat your oven to 425 degrees F. Line a baking sheet with parchment paper.
Remove the chilled dough from the refrigerator and unwrap. Top with a second sheet of plastic wrap (like a sandwich - plastic, dough, plastic)
1 Gluten Free Pie Crust
Use a rolling pin to roll the dough out between the two sheets of plastic wrap. It should be about 12-13 inches across.
Remove the top sheet of plastic wrap and flip your dough onto your lined baking sheet.
Stick the rolled dough and the baking sheet into the freezer about 15 minutes.
Remove from freezer and take off the top piece of plastic wrap. Top the dough with the berries. Do not include the liquid. Leave an edge all the way around about 1 ½" wide.
Carefully fold the edge over the berries creating a crust.
Brush the crust with the egg wash. (optional)
1 Egg wash
Bake in preheated oven on the lowest rack for 45 minutes.
Notes
Make it Vegan: Omit the egg wash.Storage: Wrap the galette in aluminum foil and store in the refrigerator. Store for up to 3 days.