Creating the Sourdough Galette With Peaches & Blueberries is easy if you follow these steps:

1. Make the Dough: In a large bowl, combine the flour and salt. Add the chilled butter and mix until the mixture resembles coarse crumbs.
2. Add Sourdough Starter: Stir in the active sourdough starter until combined. If the mixture is too dry, add ice water, one tablespoon at a time, until the dough holds together.
3. Chill the Dough: Form the dough into a disc, wrap it in plastic wrap, and refrigerate for at least 30 minutes.
4. Prepare the Fruit Filling: In a bowl, combine the sliced peaches, blueberries, granulated sugar, cornstarch, and vanilla extract. Toss gently to coat the fruit.
5. Preheat the Oven: While the dough is chilling, preheat your oven to 375°F (190°C).
6. Roll Out the Dough: On a floured surface, roll out the chilled dough into a 12-inch circle, about ¼ inch thick.
7. Transfer to Baking Sheet: Carefully transfer the rolled dough to a parchment-lined baking sheet.
8. Add the Filling: Spoon the fruit mixture into the center of the dough, leaving about a 2-inch border.
9. Fold the Edges: Gently fold the edges of the dough over the filling, overlapping as needed.
10. Brush with Egg Wash: Brush the folded edges with the beaten egg for a golden finish.
11. Bake: Bake the galette for 30-40 minutes or until the crust is golden brown and the fruit is bubbly.
12. Cool: Remove from the oven and let it cool for about 10 minutes before serving.
13. Dust with Powdered Sugar: For an added touch, dust the top with powdered sugar before slicing.

Following these steps will help you create a stunning and delicious Sourdough Galette With Peaches & Blueberries.