Step 1

Preheat the oven to 400°F. Remove the pie shell from the freezer and thaw it until just soft enough to easily prick with a fork (10 to 20 minutes). Prick the bottom and sides all over with a fork and bake on the center rack until lightly golden, 10 to 15 minutes. Don't worry if the crust cracks while baking; see note below on how to fix it. Turn the oven down to 325°F.

Step 2

Melt the butter in small sauté pan over medium-low heat. Add the leeks and season with a bit of salt and pepper. Cook over medium-low heat, stirring occasionally, until very soft, about 15 minutes. Do not brown. Taste and adjust seasoning (they should be well-seasoned). Set aside to cool.

Step 3

In a medium bowl, whisk together the heavy cream, eggs, thyme, nutmeg, Parmigiano Reggiano cheese, 1/4 teaspoon salt and 1/4 teaspoon pepper. Mix well.

Step 4

Spread the cooked leeks over the pre-baked pie shell, taking care not to puncture the crust (it may be fragile around rim, or where there are air bubbles). Pour the egg mixture over top. Bake at 325°F for 45 to 55 minutes, or until the custard is set and puffed. The quiche will deflate as it cools. Slice into wedges and serve hot or warm.

Step 5

Notes: Be sure to clean the leeks well, especially between leaves where there can be a lot of grit.

Step 6

Note: Don't panic if your crust cracks -- you can easily fix it. Make a smooth paste by mixing 1 tablespoon of flour with 1 tablespoon of water. Use your fingers to patch up and fill any cracks, then place the crust back in the oven for a minute or so to set. It should be good as new.

Step 7

Freezer-Friendly Instructions: The quiche can be frozen for up to 3 months. Remove the quiche from the freezer about 24 hours prior to serving and reheat it, covered with foil, in a 300°F oven until hot in the center.