Baked brie and caramelized vegetable pie

A vegetarian centerpiece inspired by baked Brie this caramelized vegetable pie cuddles creamy, earthy molten cheese with a bevy of autumnal vegetables: roasted butternut squash, seared mushrooms, herbed brussels sprouts and tangy red onions, and enrobes the whole mixture in store-bought puff pastry.

Ingredients

• Serves: 8-10
• This pie is relatively easy to engineer but it does require some patience. You’ll want to let it rest 30 minutes to 1 hour before cutting, to allow the puff pastry to maintain its structure — and for the cheese to firm up a bit before carving.
• Cook the individual components at your leisure, even a few days in advance, and you’ll need only to assemble the pie and bake it off before dinner.

For the filling

• 6 tablespoons extra-virgin olive oil
• 10 ounces fresh shiitake mushrooms (or creminis or other small mushrooms), stemmed and sliced
• Salt and pepper
• 2 teaspoons soy sauce
• 1 small butternut squash, peeled and cut into ½-inch cubes (about 4 cups)
• 1 tablespoon honey
• 1 pound brussels sprouts, trimmed, halved and thinly sliced (about 4 cups)
• 2 large shallots, minced (about 1 cup)
• 2 garlic cloves, minced
• 2 teaspoons minced fresh rosemary
• 1 medium red onion (about 10 ounces), halved and thinly sliced
• 1 teaspoon fresh thyme leaves
• 1½ tablespoons light brown sugar
• 1 tablespoon balsamic vinegar

For assembly

• All-purpose flour, as needed for dusting
• 2 sheets puff pastry from 1 (17- or 18-ounce) package, thawed in fridge for 24 hours
• 1 egg, beaten
• 1 whole (7- or 8-ounce) round Brie or Camembert

Procedure

1. Heat oven to 425/218 degrees.
2. In a large cast-iron or non-stick skillet, heat 2 tablespoons oil over medium-high. Add the mushrooms, season with salt and pepper and cook, stirring occasionally, until lightly browned and tender, 8 to 10 minutes. Transfer mushrooms to a large bowl, drizzle with soy sauce and toss to coat.
3. While the mushrooms cook, prepare the squash: On a large, foil-lined rimmed baking sheet, toss the squash with 1 tablespoon olive oil and the honey; season generously with salt and pepper. Spread out evenly then roast just until tender, about 15 minutes.
4. Heat 2 tablespoons oil in the skillet over medium-high. Add the brussels sprouts, shallots, garlic and rosemary; season with salt and pepper. Cook, stirring frequently, until tender and lightly caramelized, about 8 minutes.
5. Transfer the cooked brussels sprouts and squash to the bowl with the mushrooms. Stir to combine and generously season to taste with salt and pepper.
6. Wipe out the skillet, then heat the remaining 1 tablespoon oil over medium. Add the onion and thyme, season with salt and pepper, and cook, stirring occasionally, until lightly caramelized, about 10 minutes. Stir in the brown sugar, vinegar and ¼ cup water. Reduce the heat to medium-low and cook, stirring occasionally, until jammy, 10 to 15 minutes. Set aside. (Let the onion jam and vegetable filling cool completely at room temperature — or refrigerate for about 30 minutes to speed things up — before assembling the pie. If preparing in advance, you can cover and refrigerate them overnight or up to 3 days.)
7. When ready to bake your pie, line a large rimmed baking sheet with parchment paper. Working on a lightly floured surface, with a lightly floured rolling pin, roll out one sheet of puff pastry into a 10-inch square, then, using a sharp paring knife, cut it into a 10-inch circle. (If you have a 10-inch plate, you can use that as a guide.) Transfer to the baking sheet. Roll out the remaining sheet of pastry into a 12-inch square, then cut it into a 12-inch circle. If desired, decorate the top by arranging the scraps on top, or carve a light pattern into the top of the puff pastry using the tip of a sharp paring knife. (Be careful not to cut all the way through.)
8. Add half the vegetable mixture to the 10-inch round and arrange in an even layer, leaving a 1-inch border. Center the cheese on top; spoon the onion mixture over the cheese. Pat the remaining vegetable mixture evenly and tightly around the cheese, ensuring that the 1-inch border is clear.
9. Brush the exposed edges of the bottom pastry with the beaten egg. Fold the remaining piece of pastry in half, set it over the filling and unfold, carefully pushing out any air between the filling and pastry. Press the edges to seal and trim if you’d like to perfect the shape. Brush all the exposed puff pastry lightly with the beaten egg.
10. Bake until the puff pastry is deeply golden, 40 to 45 minutes. Let cool for 30 minutes to 1 hour. (If you cut the pie early, the cheese will flow out like lava; be patient and it will be molten but less messy.) Transfer to a platter and serve.