Prepare a homemade or store-bought crust in advance so it can be chilled and partially baked (up to 3 days in advance).
Preheat oven to 375°F.
Place crust in ungreased quiche, pie or tart dish.
Cover with parchment paper to fill mold. Fill dish with pie weights (or beans).
Bake 15 minutes or until edges are slightly golden. Remove parchment and pie weights. Using a fork, prick holes and bake 7 minutes and bottom of crust appears set and no longer wet. Remove from oven and allow to cool (or cover and refrigerate if making ahead) before filling.
Reduce oven to 350°F.
Place chopped bacon in frying pan and cook over medium heat, stirring occasionally until done. Place bacon on paper towels to absorb excess grease.
In a large mixing bowl or stand mixer fitted with the whisk attachment, beat eggs, cream, salt and pepper 1 minute on high or until well combined.
Whisk in bacon, onion, gruyere, parmesan, nutmeg, salt, pepper and thyme.
Pour filling into crust. Tent or use a pie crust shield to prevent over browning. Bake 35-40 minutes or until edges are set. Center should be slightly jiggly when you tap on the edge of the dish. Do not overbake.
Allow to cool 10-15 minutes before slicing to serve. Optional: Garnish with herbs, cheeses, etc. Serve warm or at room temperature.
Substitutions Mini Quiche - Use a large cookie cutter to cut pie dough to fill muffin tin or phyllo shells on a sheet pan. Fill with custard and toppings. Bake 25 minutes or until edges are set and center is slightly jiggly.Make Ahead - Quiche can be made ahead of time and then reheated. You can simply put your quiche together as directed, and bake from refrigerated when you're ready. You do run the risk of a soggy crust with this method, though.Another option is to bake your quiche fully, then let it cool before refrigerating or freezing and reheat to serve. You can also blind bake your crust and prep your filling and store them separately in the fridge, combining to bake when you're ready.
At Room Temperature - quiche can sit on your counter for no longer than two hours during serving.
Refrigerate - Wrap in an airtight container and store for up to three days.
Freeze - In an airtight container, quiche can be frozen for up to three months. While it may last longer, it will begin to lose its fresh flavor after that point.