01 - In a large bowl, whisk together flour and salt. Add cold butter and rub into the flour using fingertips until mixture resembles coarse crumbs. Gradually add ice water, mixing until dough just comes together. Shape into disk, wrap in plastic, and refrigerate at least 30 minutes.
02 - Preheat oven to 400°F. Line a baking sheet with parchment paper.
03 - Toss zucchini, bell pepper, red onion, and cherry tomatoes with olive oil, salt, and pepper. Spread evenly on the prepared baking sheet and roast 15–20 minutes until slightly tender. Allow to cool.
04 - On a lightly floured surface, roll dough into a 12-inch circle. Transfer carefully to the parchment-lined baking sheet.
05 - Arrange roasted vegetables in the center of dough, leaving a 2-inch border. Sprinkle with goat cheese and thyme leaves.
06 - Fold edges of dough over filling, pleating as needed. Brush crust with beaten egg mixed with milk.
07 - Bake for 25–30 minutes until crust is golden and crisp. Cool for 10 minutes before slicing.