Preheat oven to 350°F. Line pie shell with parchment and fill with pie weights, dry beans, or raw rice. Bake 30 minutes. Remove weights and parchment; bake until crust is cooked through and golden brown, 15 minutes more. Let cool completely on a wire rack.
In a large bowl, whisk eggs and salt until blended. Add cream and milk and whisk to incorporate fully. Set aside. In a small bowl, mix together Jarlsberg and Grana Padano. Layer one-third of cheese mixture in pie shell. Next, layer half of mushrooms, followed by half of shallots, and then half of bacon. Repeat these four layers, beginning with half of remaining cheese, and ending with rest of cheese. Pour egg mixture over layers. Cover edge of crust with foil to prevent overbrowning.
Bake quiche, rotating pan 180 degrees halfway through, until filling is set, 40 to 50 minutes. Transfer to a wire rack and let cool about 10 minutes, if serving immediately. If freezing, let cool to 70°, then transfer to refrigerator and chill to 40°.
Freezing: If freezing whole quiche, wrap in two layers of plastic. Label and date, and freeze up to 3 months. To freeze individual portions, cut quiche into 8 slices and arrange on a rimmed baking sheet. Freeze at least 4 hours and up to overnight for a formative freeze. Wrap each frozen slice in plastic, place all of the slices in a resealable plastic bag, label and date, and return to freezer for up to 1 month.
Reheating: If reheating whole quiche, unwrap, place in a cold oven, and heat to 325°. When oven reaches temperature, bake until warm throughout or a thermometer inserted into center registers 150°, 60 to 70 minutes. If reheating individual slices, unwrap, place on a rimmed baking sheet, place in a cold oven, and heat to 325°. When oven reaches temperature, bake until warm throughout, 10 to 15 minutes.
Cook's Notes
Reprinted from It's Always Freezer Season, copyright © 2021 by Ashley Christensen and Kaitlyn Goalen. Published by Ten Speed Press, an imprint of Penguin Random House LLC.
