Preheat your oven to 375°F (190°C). Press the pie crust into a 9-inch deep-dish pie plate. Crimp the edges. Line the crust with parchment paper and fill with pie weights or dried beans. Bake for 15-20 minutes until the edges are lightly golden. This is called blind baking and is the secret to a crisp crust.
While the crust is baking, cook the diced bacon in a large skillet over medium heat until crisp. Remove the bacon with a slotted spoon and drain on a paper towel-lined plate, reserving 1 tablespoon of bacon fat in the skillet. Add the finely chopped shallot to the skillet and sauté for 2-3 minutes until soft and translucent.
In a large mixing bowl, whisk together the lightly beaten eggs and heavy cream until smooth. Stir in the salt, black pepper, and freshly grated nutmeg to create the custard filling.
Remove the pie weights and parchment paper from the crust. Sprinkle the shredded Gruyère cheese evenly over the bottom of the pre-baked crust. Top with the cooked bacon and sautéed shallots.
Carefully pour the egg and cream mixture over the bacon and cheese. Be careful not to overfill. Bake for 35-40 minutes, or until the center is just set (it should have a slight jiggle) and the top is golden brown. A knife inserted near the center should come out clean.
Let the quiche cool on a wire rack for at least 10 minutes before slicing and serving. This allows the custard to set completely. Serve warm or at room temperature.
Notes
Chef's Notes: For the best flavor, use high-quality thick-cut bacon and freshly shredded Gruyère cheese. Don't skip the step of blind baking the crust; it prevents a soggy bottom. Variations: You can add 1 cup of sautéed spinach (well-drained) or mushrooms for extra vegetables. Swiss or cheddar cheese can be substituted for Gruyère. Storage: Store leftover quiche covered in the refrigerator for up to 3 days. Reheat individual slices in the oven or microwave.