For the crust:

• 1 cup all-purpose flour (120 grams)
• 1 cup cake flour (120 grams)
• ½ teaspoon salt
• 1 cup unsalted butter, cut into cubes (226 grams)
• 6 tablespoons ice cold water (90 ml)

For the filling:

• ¾ lb brussels sprouts, quartered (340 grams)
• 2 tablespoons olive oil
• 1 cup whole milk (237 ml)
• 1 cup heavy cream (237 ml)
• 3 large eggs
• 2 large egg yolks
• 1 teaspoon coarse salt
• ½ teaspoon freshly ground pepper
• ⅛ teaspoon freshly grated nutmeg
• ⅓ cup minced onion (50 grams)
• 1 ⅓ cup shredded gruyere cheese (113 grams)

To prepare the crust:

1. Combine the all-purpose flour, cake flour, and salt in a large bowl. Add the cold unsalted butter cubes and use two knives or a pastry blender to cut the butter into the dry ingredients until the mixture resembles coarse crumbs with some pea-sized pieces of butter remaining. Gradually add the ice-cold water, mixing just until the dough comes together into a cohesive ball. It’s okay if it’s a little crumbly; avoid overmixing. Shape the dough into a flat disc, cover tightly with plastic wrap, and chill in the refrigerator for at least 2 hours, or ideally overnight, and up to 5 days. This chilling step is crucial for developing flavor and creating a flaky texture.
2. Preheat your oven to 350° F (175° C). Prepare a round 9-inch x 2-inch cake pan by lining it with parchment paper (see Notes for alternative pie pan usage). This helps with easy removal of the quiche after baking.
3. On a lightly floured surface, roll out the chilled pie crust dough into an approximate 12-inch circle. Carefully transfer the rolled-out dough to your prepared cake pan, gently pressing it into the bottom and up the sides. Trim the edges, leaving about a 2-inch overhang, then tuck the overhang down into the pan to create a slightly thicker edge. This helps prevent the crust from shrinking too much. Place a sheet of well-greased parchment paper or aluminum foil directly on top of the surface of the crust. Fill completely with pie weights, dried beans, or uncooked rice, ensuring the weights fill all the way to the top of the pan to support the crust’s shape.
4. Bake the weighted crust for 20 minutes, or until the crust appears barely set. Carefully remove the top piece of parchment paper (or foil) along with the pie weights. Return the crust to the oven and bake for an additional 20 minutes, or until the crust is just barely golden brown and fully set at the bottom. This ensures a crisp, non-soggy base for your quiche. Let the blind-baked crust cool completely on a wire rack before proceeding with the filling.

To make the filling and assemble the quiche:

1. While the crust is cooling, prepare your Brussels sprouts. Increase oven temperature to 450°F (230°C). Toss the quartered Brussels sprouts with 2 tablespoons of olive oil, salt, and pepper on a baking sheet. Roast them until they are tender-crisp and beautifully golden and slightly caramelized, which typically takes about 20 minutes. Keep a close eye on them to prevent burning. Once roasted, remove from the oven and let them cool for about 5 minutes. Decrease the oven temperature to 325° F (160° C) for the quiche’s final bake.
2. In a large bowl, whisk together the whole milk, heavy cream, large eggs, egg yolks, coarse salt, freshly ground pepper, and freshly grated nutmeg until well combined and smooth. Gently stir in the cooled roasted Brussels sprouts and the minced onion. Sprinkle half of the shredded Gruyere cheese evenly in the bottom of your cooled, blind-baked pie crust. This layer of cheese acts as a barrier and adds a lovely flavor. Carefully pour the egg mixture over the cheese and sprouts, filling it all the way to the top edge of the crust (see Notes regarding potential overfilling). Finally, sprinkle the remaining Gruyere cheese over the top of the quiche filling.
3. Carefully transfer the filled quiche to the preheated oven (325° F / 160° C). Bake for approximately 1 hour, or until the quiche is set and the center jiggles only slightly when gently shaken, and the top is beautifully browned. Baking at a lower temperature ensures a creamy, custardy texture without overcooking the eggs. Once baked, let the quiche cool at room temperature for at least an hour before slicing and serving. This resting period allows the custard to fully set and makes for cleaner slices. Store any leftovers tightly covered in the refrigerator for up to 3-4 days.

HELPFUL TIPS

• Pie Pan Alternative: You can certainly use a standard 9-inch pie pan instead of a cake pan. If using a pie pan, there’s no need to line it with parchment paper.
• Avoid Overfilling: Depending on the depth of your pan and the exact size of your crust, you might have slightly more filling than will comfortably fit. Do not overfill the crust; it’s better to discard any leftover egg mixture than to risk spillage and an unbaked center.
• Reheating: To reheat slices of quiche, warm them gently in a microwave or for best results, in an oven at 300°F (150°C) until heated through.
• Make Ahead: The quiche can be baked entirely a day in advance and reheated, or the crust can be blind-baked and stored for a few days before filling and baking.

Recipe adapted from Food and Wine.