For the crust: In a large bowl, whisk together flour and salt. Cut in the cold butter using a pastry blender or your fingertips until the mixture resembles coarse crumbs with some pea-sized pieces of butter remaining.
Gradually add ice water, 1 tablespoon at a time, mixing until the dough just comes together. Do not overmix. Flatten the dough into a disc, wrap in plastic wrap, and refrigerate for at least 30 minutes.
Preheat oven to 375°F (190°C). On a lightly floured surface, roll out the dough into a 12-inch circle. Carefully transfer the dough to a 9-inch pie plate. Trim and crimp the edges.
Line the pie crust with parchment paper and fill with pie weights or dried beans. Bake for 15 minutes, then remove the parchment paper and weights. Bake for another 5-7 minutes, or until lightly golden.
For the filling: Scatter the cooked bacon and shredded Gruyere cheese over the bottom of the pre-baked pie crust.
In a medium bowl, whisk together eggs, heavy cream, salt, pepper, and nutmeg until well combined.
Pour the egg mixture evenly over the bacon and cheese in the pie crust.
Bake for 30-40 minutes, or until the custard is set and the top is lightly golden. If the crust edges start to brown too quickly, cover them with aluminum foil.
Let the quiche cool for at least 10 minutes before slicing and serving.
Notes
Quiche Lorraine is delicious served warm or at room temperature. It pairs well with a simple green salad.