Preparation

Make the filling

• Position a rack in the center of the oven and heat the oven to 375°F. Lightly oil an 8×8-inch baking dish.
• Toss the vegetables and rosemary with 3/4 tsp. salt and 1/2 tsp. pepper in the baking dish. Add the lemon zest, juice, and thyme; toss to combine. Cover with foil and roast until fork-tender, 30 to 40 minutes. Remove the foil and let cool.

Make the crust

• Turn the oven temperature up to 400°F.
• Pulse the flour, butter, cream cheese, and salt in a food processor until the dough begins to form pea-size pieces, about fifteen 1-second pulses. Process for 15 to 30 seconds until most of the dough forms a ball around the blade.
• Transfer the dough to a well-floured work surface and gently knead once or twice to help it come together. Dust a 12×17- inch sheet of parchment with flour. Roll the dough on the parchment into a 16-inch round that’s about 1/8 inch thick (two sides will go beyond the paper). It’s OK if it’s not a perfect circle and the edges look rough.

Assemble and bake

• Spread the goat cheese on the dough, leaving a 1-1/2-inch border. Transfer the dough on the parchment to a 13×18-inch baking sheet; the edges will hang over the sides.
• Spoon the vegetable mixture on top of the cheese, mounding it slightly in the center. Fold the edge of the dough over the edge of the filling to create pleats that are 1-1/2 inches wide. Brush the pleated dough with the beaten egg.
• Bake until the crust, including the pleats, is golden brown, 35 to 45 minutes. Transfer to a rack and let cool on the baking sheet for at least 10 minutes before serving.