If you are making the crust from scratch, you will make that first. If using a pre-made pie crust, jump below to step 7.
Make the crust: add the flour, salt and sugar into a food processor and pulse a couple of times.
1 1/2 cups All-Purpose flour, spooned and leveled, 1/2 tsp. table salt, 1 Tbsp. Granulated sugar
Add the butter and pulse again until you have little butter pieces throughout.
1/2 Cup unsalted butter, cold, cut into cubes
Slowly stream the ice cold water or vodka with the food processor on just until dough is moistened, you dont want to add too much. 3 Tbsp should be plenty to make a shaggy dough.
~3 Tbsp. ice cold water or ice cold vodka
Dump this mixture onto a lightly floured large cutting board or surface and work in butter with your fingers. Fold and form the dough gently. Knead dough until somewhat smooth. Don’t over work the dough, you won’t get flakey pie crust that way. :) Wrap the dough in plastic wrap and chill in the fridge for at least 45 minutes or up to 2 days.
Once chilled, roll out the dough on a lightly floured surface using a rolling pin to a 14" round.
Transfer the dough to a 9" metal or ceramic pie pan/pie plate (not glass). Trim away any overhang and reserve any scraps for patching. You can fold the edges of the pie crust under and pinch the edge to make the crust edge and thicker even and so it stands up.
Decorate the pie crust edge, I like the fluted look with the thumb and index finger of one hand, pinch the edge of the crust. Press down between the two fingers with the index finger of the other hand.
Chill the dough in the fridge for 30 minutes. Then, line the dough with 2 layers of overlapping parchment paper and fill with pie weights, pressing them all the way to the sides so the dough doesn’t shrink down. You will need 2 set of pie weights. Or if you don't have pie weights you can always use dried beans. Bake in the oven at 350°F for 20 minutes. Remove from oven and remove pie weights and parchment paper. Before putting back in the oven without the weights, prick the bottom crust with a fork all over to prevent it from puffing up and bake for an additional ~10 minutes just until crust begins to brown. Let this cool while you make the filling.
Sauté the spinach in a frying pan on the stove over medium heat until cooked down. Set aside to cool.
5 oz. spinach, sautéed
Whisk together the eggs, 1 1/2 cups white cheddar, Parmesan, heavy cream, and pepper. Then add in spinach and mix again.
4 large eggs, 1 1/2 cups heavy cream, 2 cups extra sharp white cheddar, shredded, divided, 1/2 cup Parmesan, grated, 1/2 tsp. pepper
Sprinkle 1/4 cup cheese down onto the crust, followed by the filling and then top with the remaining white cheddar.
Bake for 40-45 minutes at 350°F or until the edges are set but it still jiggles just a little in the center of the quiche.
Cool the quiche for at least 20 minutes, but I always let it rest for a few hours or overnight in the refrigerator to let it set up completely. It's too delicate and fragile right out of the oven to slice into it right away. Ideally you want the quiche to cool in the pan before serving! Enjoy cold, room temperature or warmed.