1. Make the pastry dough: In a food processor, combine the flour and salt. Add the chilled butter and pulse until the mixture resembles coarse crumbs. Add the ice water and pulse until the dough just begins to come together. Gather the dough into a disc, wrap in plastic, and refrigerate for at least 1 hour.

2. Prepare the apple filling: In a large bowl, toss the sliced apples with the granulated sugar, brown sugar, cinnamon, and nutmeg until well coated.

3. Make the miso caramel: In a small saucepan, whisk together the miso paste, heavy cream, butter, and maple syrup. Bring to a simmer over medium heat, stirring occasionally, until the sauce thickens, about 5-7 minutes. Remove from heat and set aside.

4. Assemble the galette: Preheat the oven to 400°F. On a lightly floured surface, roll the chilled dough into a 12-inch circle, about 1/4-inch thick. Transfer the dough to a parchment-lined baking sheet. Arrange the apple slices in concentric circles, leaving a 2-inch border. Fold the border of the dough over the apples, pleating as you go.

5. Bake the galette: Bake for 35-40 minutes, or until the crust is golden brown and the apples are tender. Drizzle the warm miso caramel sauce over the top of the galette.

6. Serve and enjoy: Allow the galette to cool for 10 minutes before slicing and serving. Enjoy warm with a scoop of vanilla ice cream or a dusting of powdered sugar.