📖 Instructions

1. **For the Galette Dough:** In a large mixing bowl, whisk together the all-purpose flour, granulated sugar, and salt. Make sure it's all well combined. This dry mix sets the base for our flaky crust.
2. Add the cold, cubed unsalted butter to the dry ingredients. Using a pastry blender, two knives, or even your fingertips, cut the butter into the flour until the mixture resembles coarse crumbs with some pea-sized pieces of butter still visible. The cold butter is key to flakiness!
3. Gradually add the ice water, one tablespoon at a time, mixing lightly with a fork until the dough just starts to come together. Be careful not to add too much water; you want it moist enough to form a ball, but not sticky. I usually start with 3 tablespoons and add more only if needed.
4. Turn the dough out onto a lightly floured surface and gently gather it into a disk. Avoid overworking the dough, as this can make your crust tough. Wrap the disk tightly in plastic wrap and refrigerate for at least 30 minutes, or up to 2 days. Chilling the dough is super important for an easy roll-out and a tender crust.
5. **For the Strawberry Rhubarb Filling:** While the dough chills, prepare your fruit. In a large bowl, combine the hulled and sliced strawberries and the chopped rhubarb. If your rhubarb pieces are very large, halve them lengthwise.
6. Add the granulated sugar, cornstarch, lemon juice, and vanilla extract to the fruit. Gently toss everything together until the fruit is evenly coated. The sugar helps draw out juices and the cornstarch will thicken the filling, preventing a soggy bottom. Let this mixture sit for about 15 minutes to macerate.
7. **Assemble the Galette:** Preheat your oven to 400°F (200°C). Line a large baking sheet with parchment paper. This will make cleanup a breeze and prevent sticking.
8. 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 about making it perfectly round; the rustic look is part of its charm!
9. Carefully transfer the rolled dough (if not already on it) to the prepared baking sheet. Pour the strawberry rhubarb filling into the center of the dough, leaving a 2-inch border all around the edges.
10. Gently fold the edges of the dough over the fruit filling, pleating it as you go. The center of the galette should remain open, revealing the colorful fruit. Again, embrace the rustic look – imperfections are beauty here!
11. In a small bowl, whisk together the egg yolk and water for the egg wash. Using a pastry brush, lightly brush the folded dough edges with the egg wash. This helps achieve that beautiful golden-brown crust.
12. Sprinkle the turbinado sugar (also known as raw sugar) generously over the egg-washed crust. This adds a lovely sparkle and a pleasant crunch.
13. **Bake the Galette:** Transfer the baking sheet to the preheated oven. Bake for 45-55 minutes, or until the crust is deeply golden brown and the fruit filling is bubbly and thickened. If the crust starts to brown too quickly, you can loosely tent it with aluminum foil.
14. Once baked, remove the galette from the oven and let it cool on the baking sheet for at least 15-20 minutes before slicing. This allows the filling to set properly, so it won't be too runny when you cut into it. Serve warm, perhaps with a scoop of vanilla ice cream or a dollop of whipped cream!