Leek and Gruyère Quiche (Caramelized)

This caramelized leek quiche is an ideal recipe to make for a brunch or picnic.

flour, for work surface
½ recipe Pâte Brisée
2 Tbsp. extra-virgin olive oil
3 leeks, whites and light green parts only, halved lengthwise, sliced crosswise ¼" thick
2 tsp. fresh thyme leaves
coarse sea salt
black pepper, freshly cracked
1½ cups Gruyère cheese, freshly grated
3 large eggs
1 large egg yolk
½ cup milk
½ cup heavy cream

On a lightly floured surface, roll out dough to a 12" circle. Fit dough into a 10" round fluted tart pan with a removable bottom, pressing into edges. Trim dough to a ½" overhang all around. Fold edge of dough over to create an edge that extends ¼" above the pan. Lightly prick bottom of dough all over with a fork. Chill until firm about 30 minutes.

Preheat oven to 375°F (190°C/170°C fan, Gas Mark 5).

Line bottom of dough with parchment paper, leaving at least a 1" overhang. Fill with pie weights or dried beans.

Bake until the edges are just beginning to turn golden, about 30 minutes. Remove parchment paper and weights; continue baking until lightly golden all over, 10-15 minutes more. Cool tart shell completely on a wire rack.

Heat olive oil in a medium skillet over medium heat. Add leeks and thyme and cook, stirring occasionally, until leeks soften and begin to brown, 10-15 minutes. Season with salt and pepper.

Sprinkle half of the cheese over the bottom of the tart shell, top with cooked leek mixture and sprinkle with remaining cheese. In a medium bowl, whisk together eggs, yolk, milk, cream, and a pinch of salt and pepper.

Pour mixture over leeks and cheese.

Bake until puffed and golden brown, 30-35 minutes. Transfer to a wire rack to cool 10 minutes before serving, or serve at room temperature.

Makes 1-9” tart.