Ingredients:
2 tablespoons(30 grams) extra-virgin olive oil
6 large shallots (about 180 grams), peeled, halved, and thinly sliced
3/4 teaspoon(4 grams) kosher salt
1 teaspoon(3 grams) freshly ground black pepper
1 tablespoon(15 grams) sherry vinegar
All-purpose flour (for rolling)
1 recipe Rough Puff Pastry (see Author Notes)
2 pounds(about 907 grams) thick asparagus, or 1½ pounds (about 570 grams) thin/pencil asparagus, woody ends generously trimmed and discarded (you’re aiming for pieces of asparagus about 5 inches/13 centimeters long)
12 ounces(340 grams) Brie, cut into thick slices
Egg wash (1 large egg plus 1 tablespoon water), for brushing
Sesame seeds, for sprinkling
Directions:
In a medium skillet over medium heat, warm the oil. Cook the shallots, stirring occasionally, for 4 to 5 minutes, until softened and translucent. Add the salt and pepper and reduce the heat to low. Continue to cook, stirring occasionally, for 20 to 25 minutes, until the shallots have begun to brown. Stir in the vinegar and let cool completely.
On a lightly floured surface, roll out the dough to a rectangle about 20×20 inches/50×50 centimeters, slightly thicker than ¼ inch/6 millimeters. If the dough feels soft at this point, use the rolling pin to unfurl onto a parchment-lined baking sheet and chill before proceeding.
Using a pastry wheel, bench scraper, or sharp knife, divide the dough into 8 pieces and form into squares (each about 5×5 inches/13×13 centimeters). Divide the shallots evenly among the dough, spreading in an even layer in the center.
Divide the asparagus into 8 even portions. Divide the Brie into 8 even portions, each about 1½ ounces (43 grams). Line a baking sheet with parchment paper.
Working with one piece of dough at a time, place on the prepared baking sheet. Arrange one portion of asparagus in a bundle in the center, then place one portion of Brie on top. Fold one of the points inward toward the center of the square. Brush the exposed dough with the egg wash, then fold the opposite corner in, pressing on the dough to seal. Brush any remaining exposed dough with the egg wash. Sprinkle the dough generously with the sesame seeds. Repeat with the remaining pieces of dough, asparagus, and Brie. Refrigerate for at least 15 minutes or up to 1 hour.
Toward the end of the chill time, arrange a rack in the lower third of the oven, preferably with a baking steel or stone on it; heat the oven to 425°F/218°C.
Bake the pies (on the steel/stone, if using) for 30 to 35 minutes, until the crust is deeply golden brown and the asparagus is tender. Let cool for at least 5 minutes before serving warm (they are also delicious at room temperature).