French Onion Soup and Apple Galette

**Make the Dough:** In a large bowl, whisk together flour and salt. Cut in cold butter using a pastry blender or your fingers until the mixture resembles coarse crumbs. Gradually add ice water, 1 tablespoon at a time, mixing until the dough just comes together. Flatten the dough into a disc, wrap in plastic wrap, and refrigerate for at least 30 minutes.

**Caramelize the Onions:** Heat butter and olive oil in a large skillet over medium-low heat. Add sliced onions and cook, stirring occasionally, until softened and deeply golden brown, about 25-30 minutes. Stir in brown sugar and balsamic vinegar during the last 5 minutes of cooking. Remove from heat and stir in fresh thyme. Season with salt and pepper.

**Assemble the Galette:** Preheat oven to 400°F (200°C). Line a baking sheet with parchment paper. On a lightly floured surface, roll out the dough into a 12-inch circle. Transfer the dough to the prepared baking sheet.

Spread the caramelized onions evenly over the dough, leaving a 2-inch border. Arrange apple slices on top of the onions. Sprinkle with shredded Gruyere cheese.

Fold the edges of the dough over the filling, pleating as you go. In a small bowl, whisk together the egg and water for the egg wash. Brush the egg wash over the crust.

Bake for 30-40 minutes, or until the crust is golden brown and the filling is bubbly. Let cool slightly before slicing and serving.