01 - Set the oven temperature to 400°F and line a baking sheet with parchment paper.
02 - In a large bowl, combine flour and salt. Cut in cold butter until mixture resembles coarse crumbs. Gradually add ice water, mixing just until dough forms. Shape into a disk, wrap, and refrigerate for 20 minutes.
03 - Toss zucchini, eggplant, bell pepper, and onion with olive oil, salt, and pepper. Spread on the prepared baking sheet and roast for 15 minutes. Let cool slightly.
04 - On a lightly floured surface, roll chilled dough into a 12-inch diameter circle. Transfer to the parchment-lined baking sheet.
05 - Arrange roasted vegetables in the center of the dough, leaving a 2-inch border. Sprinkle with crumbled goat cheese and fresh thyme leaves.
06 - Fold the dough edges over the filling, creating pleats as needed. Brush the crust with beaten egg.
07 - Bake for 25 to 30 minutes or until the crust is golden brown and crisp.
08 - Allow to cool for 5 minutes before slicing and serving.