A mixture of Cook's Illustrated, Martha Stewart, and trial & error.
1 1/4 cups flour
4 tbsp butter, cubed (frozen or very cold)
3 tbsp shortening, cubed (frozen or very cold)
1 tbsp sugar
1 tsp salt
Preheat oven to 375. Process dry ingredients to blend, then add shortening and process for ten one-second pulses. Add butter and repeat. Turn into a mixing bowl and fold in ice water with a spatula, 1-2 tbsp at a time, until the dough coheres into a slightly tacky ball. Turn out onto plastic wrap and squish into a 4 inch disk, then freeze for 30 minutes. Roll out with a little extra flour, rotating after each couple of rolls. Fold in quarters and unfold in a deep quiche pan, turning in any overhang and pressing against the sides. Lightly fork the bottom several times and freeze for 30 minutes. Bake for 25 minutes (pie weights may be used). Remove pie weights if necessary and bake for 5 more minutes. Remove from oven and let cool. (Do not add cheese later if the crust is still hot enough to melt it.)
10 oz. raw spinach, chopped and large stems removed (no frozen spinach)
1 tbsp butter
4 oz Gruyere cheese
1 cup heavy whipping cream (do not substitute!)
1 cup milk
2 eggs and 2 egg yolks
1 tsp salt
1 tsp white pepper
1 dash ground nutmeg
While crust is baking, saute shallots in butter in a large, deep pan until translucent. Add spinach, a little at a time, until it is uniformly wilted. Remove, place in strainer, and allow to drain liquids, pressing firmly to encourage this. While the spinach drains further, grate the cheese finely. Beat spices with eggs, then add milk and cream and whisk together.
Alternate layers of the drained and pressed spinach (the spinach should not dribble even a little) and the finely grated cheese in the cooled pie shell, spinach first. Place the quiche pan on a rimmed cookie sheet, pull out the oven rack, and put the whole thing on the rack. Then gently pour the filling liquid into the pan, making sure not to pour all in one spot. Gingerly slide the rack back into the oven.
Bake at 375 for 35-50 minutes, or until top has golden brown spots and the center jiggles only slightly. (Check at 35 and 45 minutes.) Allow to cool at least 10-15 minutes before removing the quiche from the pan.
Follow all directions exactly and happiness will be yours. This filling also works with 4-5 slices of roughly crumbled or chopped bacon in place of the spinach and shallots. Note: Do not add the spices to the milk and then the eggs. Do not grate the cheese too early or with the coarse side of the grater. Do not use half and half in place of the milk and cream. Do not skimp the draining of the spinach. Do not use vodka in the crust---I don't care what you heard. Do not touch the dough directly with your hands except when flipping it to roll and when folding and unfolding it and patting it into the pan. Touch the butter and shortening as little as possible. Do not use all butter; shortening will not kill you. If you use a shallow quiche pan, the baking time will be shorter and you will not have a huge, thick, beautiful slab of quiche. If you don't put the pan on a cookie sheet and your crust develops an invisible crack and leaks egg all over the oven, don't come crying to me.