Brie & Caramelized Onion Quiche Recipe

Make dough

In a medium bowl, combine 1.5 cups all-purpose flour and 0.5 tsp salt. Add 6 tbsp cold cubed unsalted butter. Using a pastry cutter or fingertips, cut the butter into the flour until mixture resembles coarse crumbs with some pea-sized pieces remaining.

Add water and chill

Sprinkle 3 tbsp ice water over the flour-butter mixture, stirring gently with a fork until dough just comes together. Add another tablespoon of water only if dry. Form dough into a flat disk, wrap in plastic, and chill in refrigerator for at least 30 minutes (or up to 2 days).

Blind bake shell

Preheat oven to 400°F (200°C). On a lightly floured surface, roll chilled dough to a 12-inch circle about 1/8 inch thick. Fit into a 9-inch (23 cm) tart pan or pie dish, trim and crimp edges. Chill in freezer 10 minutes. Line crust with parchment paper and fill with pie weights or dried beans. Bake for 15 minutes, remove weights and parchment, bake another 8–10 minutes until lightly golden. Reduce oven temperature to 375°F (190°C). If using, whisk 1 egg and brush crust interior, then bake 2 minutes to seal (optional). Let cool a few minutes.

Caramelize onions

While dough chills or bakes, heat 1 tbsp olive oil and 1 tbsp unsalted butter in a large skillet over medium-low heat. Add 2 cups thinly sliced yellow onions and 0.5 tsp salt. Cook, stirring every few minutes, for about 20–30 minutes until onions are deep golden and caramelized. If onions begin to stick or brown too fast, lower heat and add a splash (1–2 tbsp) water. Stir in 0.5 tsp granulated sugar, 0.25 tsp freshly ground black pepper and 0.5 tsp fresh thyme leaves (if using) for the last 2 minutes. Transfer onions to a bowl and let cool slightly.

Prepare custard

In a medium bowl, whisk together 4 large eggs, 1.25 cups half-and-half, 0.125 tsp grated nutmeg, 0.75 tsp salt and 0.25 tsp freshly ground black pepper until smooth and slightly frothy. Taste and adjust seasoning lightly.

Assemble quiche

Spread half of the caramelized onions evenly over the pre-baked crust. Arrange Brie slices (about 8 oz total) evenly on top of the onions, leaving small gaps between slices. Spoon remaining onions over the Brie. Pour the egg-half-and-half mixture evenly into the crust, covering the cheese and onions. Lightly tap the pan on the counter to release air bubbles. Sprinkle 2 tbsp grated Parmesan over the top if using.

Bake

Place quiche on a baking sheet and bake at 375°F (190°C) for 30–40 minutes, or until the custard is set around the edges but still slightly jiggly in the center (internal temperature ~170°F / 77°C). If the crust browns too quickly, tent loosely with aluminum foil for the last 10–15 minutes.

Rest

Remove quiche from oven and let rest on a wire rack for 15–20 minutes to finish setting. This improves sliceability.

Sprinkle 0.25 tsp coarse sea salt lightly over the top and garnish with fresh thyme sprigs before slicing. Serve warm or at room temperature.