Remove dough from refrigerator and place on countertop or marble pastry board. Let rest for several minutes. Line two large baking sheets (preferably rimless) with parchment paper.

If working on a countertop, unwrap plastic or parchment from dough, but keep it underneath the bottom of the round. Place another layer of plastic or parchment on top. The layers will prevent dough from sticking. If using a pastry board, dust both the board and your rolling pin with a thin layer of flour.

Roll out your dough into a 12-14 inch round, with a 1/8 inch thickness (it doesn't need to be uniform). Work as quickly as possible to prevent the dough from getting warm. Transfer to a parchment lined baking sheet, either directly on a rimless sheet, or on the underside of a rimmed sheet. You want to be able to easily slide the pie off your pan once baked. Chill dough in the refrigerator for 30 minutes, until firm. If making a second galette, repeat the same process with the second batch of dough.

While the rolled dough is chilling, mix stone fruit slices, berries, sweetener, and seasonings in a large bowl, then set aside. Preheat oven to 400 degrees.

Once rolled dough is chilled, remove pan from refrigerator and set on countertop. Sprinkle the center with almond flour or ground cookies, leaving a 2-3 inch perimeter border. Place fruit in crust, on top of the flour/ground cookies, arranging stone fruit slices in a concentric circle if desired. Again leave a 2-3 inch border around the edges. Trim excess dough around edges and set aside.

Fold up edges of the dough around the fruit center, tucking, crimping, and pleating as you move around the circle. Be sure there are no large cracks in the crust, so your filling will not ooze out during baking. Use remaining dough scraps to patch cracks if needed. Brush the exposed top of the dough with egg wash, and sprinkle with Demerara sugar.

Bake in the center of the oven for 35-45 minutes, until the filling is bubbling and the crust is golden brown. Remove from oven and let the galette cool on the pan for 5 minutes, then carefully transfer it to a cooling rack using the parchment paper overhang to drag it from the pan. Once on the rack, gently slide the paper out from beneath the galette. Let rest on the cooling rack for 15 minutes.

Garnish with fresh mint leaves, and serve warm, with ice cream, whipped cream, or coconut cream.