Preheat your oven to 375°F (190°C). Unroll the pie crust into a 9-inch pie dish. Press it gently into the bottom and sides, then prick the bottom with a fork.
Heat a skillet over medium heat and cook the chopped bacon until crispy. Transfer it to a paper towel-lined plate to drain.
Sprinkle the grated Gruyère cheese evenly over the bottom of the pie crust. Scatter the crispy bacon on top.
In a mixing bowl, whisk together the eggs, heavy cream, whole milk, salt, black pepper, and ground nutmeg until well combined.
Carefully pour the egg mixture over the bacon and cheese, distributing the filling evenly.
Bake for 35–40 minutes, or until the edges are set, the top is lightly golden, and the center has a slight jiggle.