Step 1: In a large bowl, whisk together the flour and salt. Add the cold, cubed butter and cut it into the flour using a pastry blender or your fingertips until the mixture resembles coarse crumbs with some pea-sized pieces of butter remaining.
Step 2: Gradually add the ice water, 1 tablespoon at a time, mixing until the dough just comes together. Be careful not to overmix. Form the dough into a disc, wrap it in plastic wrap, and refrigerate for at least 30 minutes (or up to 2 days).
Step 3: Preheat your oven to 400°F (200°C). Line a baking sheet with parchment paper.
Step 4: In a separate bowl, combine the sliced fresh peaches, granulated sugar (starting with less and adding more if needed), 1 tablespoon of flour or cornstarch, lemon juice, and vanilla extract (if using). Toss gently to coat.
Step 5: On a lightly floured surface or directly on the parchment paper, roll out the chilled dough into a rough 12-14 inch circle, about 1/8 inch thick. Don't worry if it's not perfectly round; the rustic look is part of its charm. This is key for many fresh peach recipes.
Step 6: Transfer the rolled dough (if not already on it) to the prepared baking sheet. Arrange the peach filling in the center of the dough, leaving a 2-inch border around the edges.
Step 7: Gently fold the edges of the dough over the peaches, pleating it as you go to create a rustic, free-form crust. There will be an exposed center of peaches.
Step 8: Brush the folded crust with the beaten egg wash and sprinkle generously with turbinado sugar for a beautiful sparkle and crunch. This makes for beautiful fresh peach recipes.
Step 9: Bake for 35-45 minutes, or until the crust is golden brown and the peach filling is bubbly and tender. If the crust browns too quickly, you can loosely tent it with foil.
Step 10: Remove from the oven and let the galette cool on the baking sheet for at least 15-20 minutes before slicing and serving. This allows the juices to set. Enjoy this classic among fresh peach recipes!