This plum galette is a freeform alternate to a tart that celebrates stone fruit season keeping all the focus on beautiful sliced ripe plums.
1–1/4 cups plus 2 tablespoons all-purpose flour plus more for work surface
2 teaspoons plus 1/4 cup granulated sugar
1/2 teaspoon kosher salt
1/2 cup (1 stick) unsalted butter, cold and cut into cubes
1/4 cup ice cold water
8–10 plums, pitted and sliced 1/4″ thick
Zest of 1/2 lemon
1 tablespoon lemon juice
1 large egg
1 tablespoon sanding sugar
Combine 1-1/4 cups flour, 2 teaspoons sugar and salt in a large bowl. Use a fork or pastry blender to cut the butter into the flour until the mixture resembles pea-sized clumps. Use a spatula or wooden spoon to gradually fold the water into the dry ingredients. When the dough starts to form, use your hands to bring it together into a ball. Press the dough into a disk and cover with plastic wrap. Chill in the refrigerator for at least 1 hour or up to 2-3 days.
Preheat the oven to 375 degrees F.
In a large bowl, gently stir together the plums, 1/4 cup sugar, 2 tablespoons flour, lemon juice and lemon zest.
On a lightly floured work surface, roll out the dough into an 11-inch diameter circle. Transfer to a parchment paper-lined sheet pan. Start in the center and arrange the plum slices overlapping in a circular pattern, leaving a 2-inch border. Fold the dough at the edge over to meet the fruit.
Whisk together the egg with 1 tablespoon water. Brush the egg wash on the crust and sprinkle with sanding sugar. Bake for 45 minutes, until golden brown. Let cool and serve warm or at room temperature.