Ingredients for the Crust
- 2½ cups all-purpose flour
- 1½ tablespoons sugar
- ½ teaspoon fine sea salt
- 1¼ cups (2½ sticks) unsalted butter, cubed and chilled
- 2 large eggs
Ingredients for the Quiche
- 8 large eggs
- ½ cup whole milk
- ½ cup heavy cream 1 teaspoon fine sea salt
- ¾ cup shredded Gruyère cheese
- 1½ tablespoons olive oil
- 1¾ cups chopped Brussels sprouts
- About 1 large leek, halved, rinsed well, and sliced crosswise into ¼-inch-thick pieces (1 cup)
- ½ teaspoon red pepper flakes
- 1 tablespoon white wine vinegar
- 1 baked pie crust
For Pie Crust:
1. In a food processor (or a large bowl, if mixing by hand), combine the flour, sugar, and salt. Pulse once or twice to combine. Add the butter and pulse until it is broken down into pea- size pieces. (If mixing by hand, get in there with your hands and work the butter into the flour.)
2. Add the eggs and pulse (or stir by hand) until combined. The dough may still seem dry and not entirely together—that’s okay. Dump it out onto a piece of plastic wrap. Bring the dough together into a ball and flatten it into a disc on the plastic wrap; it should come together as you do, but if it is still too dry, add a teaspoon or two of very cold water. Wrap the dough tightly and refrigerate for at least 1 hour.
3. Preheat the oven to 375ºF.
4. On a well-floured work surface, roll out the dough into a round just under ¼ inch thick. Line a 9-inch pie pan with the dough. Cut the excess dough from the edge and then crimp the edge and fold it up. With a fork, gently poke the bottom of the dough all over. Line the dough with a large piece of parchment paper and fill it with dried beans or pie weights.
Bake for 15 to 20 minutes, until it starts getting golden and is almost fully cooked. Remove the parchment and beans or weights and bake for 10 minutes more, or until just lightly golden all over and fully baked. Transfer to a wire rack; keep the oven on.
1. In a medium bowl, whisk the eggs until frothy. Add the milk, cream, and ½ teaspoon of the salt and whisk again. Add the cheese and stir to combine. Set aside.
2. In a large skillet, heat the oil over medium to high heat. Add the Brussels sprouts and the remaining ½ teaspoon salt. Cook for about 8 minutes, until the Brussels sprouts just start to become tender. Add the leek and red pepper flakes. Cook for 5 to 8 minutes more. You want the Brussels sprouts to still have a bite to them, so don’t overcook them. Add the vinegar and stir to combine.
3. Pour the Brussels sprouts and leeks into the baked pie crust and spread them evenly. Pour the milk mixture evenly over the Brussels sprouts and leek.
4. Bake the quiche for 35 to 45 minutes, then cover it with foil and bake for 10 to 15 minutes more, until the center is jiggly but set.
5. Let the quiche cool, then slice and enjoy. The quiche will keep, covered, in the fridge for up to 3 days. Reheat it in the oven or microwave.