Salted Caramel Apple Galette

Name: Salted Caramel Apple Galette
Prep time: 1 h 20 min
Cook time: 35 min
Total time: 1 h 55 min
Cuisine: American
Ingredients: 1 and 1/2 cups (188g) all-purpose flour (spoon & leveled), plus more for work surface; 1/4 cup (50g) granulated sugar; 1/4 teaspoon salt; 1/2 cup (115g; 1 stick) cold unsalted butter, cubed*; 1/4 cup (60ml) ice cold water*; 2 – 3 large apples, peeled and sliced into 1/4 inch slices (about 4-5 cups slices)*; 1/4 cup (50g) packed light or dark brown sugar; 1 and 1/2 Tablespoons (12g) all-purpose flour; 2 teaspoons fresh lemon juice (to prevent apple browning); 1 teaspoon ground cinnamon; 1/4 teaspoon ground nutmeg; salted caramel sauce; egg wash: 1 large egg beaten with 1 Tablespoon milk; optional: 1/3 cup (40g) Diamond of California chopped walnuts