The sweet flavor of slow-cooked leeks complements the woodsy scent of mushrooms especially well in the creamy custard of this quiche. Although it might be delicious to use some fancy wild mushrooms in this, I’ve crafted the recipe with the white cultivated mushrooms available everywhere. I would definitely prepare the leeks and mushrooms the day before to cut down on the last-minute rush. Since they both need to cook slowly for maximum flavor, cooking them separately actually saves you time. This is a perfect appetizer for an elegant dinner.
Makes one 10-inch tart, 8 to 10 servings
One 10-inch tart crust made from Flaky Buttery Dough (see below)
4 tablespoons unsalted butter, divided use
1 pound leeks (about 2 medium), white part and 1 to 2 inches of the green part, sliced 1/4-inch thick and washed repeatedly to remove all sand
12 ounces white mushrooms, rinsed and thinly sliced
Fine sea salt and freshly ground black pepper
3 large eggs
1 cup half-and-half or light cream
1/2 cup/1 ounce finely grated Parmigiano-Reggiano, optional
2 tablespoons finely chopped flat-leaf parsley
- Melt half the butter in a medium saucepan and add the leeks. Stir to coat them and cook over medium heat until they start to sizzle. Lower the heat and cook, stirring often, until the leeks are reduced and starting to color, about 30 minutes.
- As soon as you have started the leeks, use a separate pan and the remaining butter to start cooking the mushrooms. Season them with salt and pepper, and once they start to exude their juices, cook them slowly until the juices evaporate and the mushrooms begin to color, about 30 minutes. Mix the mushrooms into the leeks, taste for seasoning, and scrape them into a bowl to cool. For advance preparation, cover and refrigerate them up to a couple of days.
- When you’re ready to bake the quiche, set a rack at the lowest level in the oven and preheat to 400°F.
- Whisk the eggs in a large bowl and season them lightly with salt and pepper. Whisk in the cream, grated cheese if using, and parsley.
- Spread the leek and mushroom mixture on the tart crust. Pour in the custard mixture, filling only to within 1/4 inch of the top of the crust.
- Carefully set the pan in the oven and immediately lower the temperature to 375°F. Bake until the crust is baked through and the filling is set and puffed, 35 to 40 minutes.
- Cool the quiche briefly on a rack, then unmold and serve it either hot or warm.
FLAKY BUTTERY DOUGH
Makes enough for 2 single-crusted pies or 1 double-crusted pie
2 1/3 cups unbleached all-purpose flour (spoon into dry-measure cup and level)
1/2 teaspoon fine sea salt
1 teaspoon baking powder
2 sticks unsalted butter, chilled and cut into 1/2-inch pieces
2 large eggs
- Combine the flour, salt, and baking powder in the bowl of a food processor; pulse several times at 1-second intervals to mix.
- Add the butter pieces and pulse again 3 or 4 times. Use a metal spatula to scrape the side of the bowl and mix the butter pieces throughout the flour.
- Pulse again 3 or 4 times.
- Using a fork, beat the eggs to break them up, then add to the bowl. Pulse again until the dough almost forms a ball; avoid pulsing too much, or the pieces of butter needed to make the dough flaky will become too small.
- Invert the dough onto a lightly floured work surface, carefully remove the blade, and quickly press the dough together.
- Divide the dough into 2 pieces, form them into thick disks, and wrap each one in plastic. Chill the dough for a couple of hours before rolling.