Put the flour, sugar, and salt in a bowl and whisk to combine. Cut the butter into 1/2-inch cubes and add it to the flour mixture. Use your fingers or a pastry cutter to cut the butter into the dry ingredients until the mixture resembles a combination of lima beans and small peas.

Add 4 tablespoons (1/4 cup) of the ice water and use a rubber spatula to toss the water and dry ingredients together. Add the remaining water and gently mix it in. The dough will feel and look wet but that is okay.

Dump the dough onto a lightly floured surface and press the dough together. Use your fingers to press it out to a 6x8-inch rectangle with the short end facing you. Fold the top third towards the center and then fold the bottom third over the top half.

Rotate the dough 90 degrees (a quarter turn) so the short edge is facing you. The edges won’t be smooth or completely even which is okay. If the dough is sticking to the work surface, add more flour.

Again, with your fingers press the dough out to a 6x8-inch rectangle. Fold the top third towards the center and then fold the bottom third over the top half. Repeat this step one more time.

Shape the dough into a round disk, 1-inch thick and wrap the dough in plastic wrap. Chill for at least 45 minutes. The dough can be refrigerated for up to 2 days.

Remove the dough from the refrigerator and roll it out to a 13-inch circle. Fold the dough into quarters and place it in a 9-inch pie plate. Unfold the dough, so the dough is overhanging the edges. Trim the edges with a sharp knife or kitchen shears so there is about 3/4-inch overhang. Fold the dough under so that the edge is even with the edges of the pie plate. Use a fork to crimp the edges.

Prick the bottom and sides of the pie dough all over with a fork. This step will help prevent the dough from puffing up during baking. Refrigerate the pie shell for 1 hour or freeze for 30 minutes.

Preheat the oven to 375°F. Place a half baking sheet in the oven.

Remove the pie crust from the refrigerator and press a large piece of foil onto the pie dough so the bottom and edges are covered. Fill the pie plate with pie weights or dried beans so the sides of the dough are completely covered.

While the pie dough is chilling in the refrigerator prep the other ingredients. Wash and partially dry the spinach. Grate the cheeses and chop the garlic.

For the leeks, slice off the root and tough dark green tops, then split the remaining white/light-green stalk lengthwise. Thoroughly wash the layers under cold running water or soak in a bowl of water, agitating to remove dirt trapped in between the layers. Pat them dry before cooking.

Add 1 tablespoon of vegetable oil to a non-stick pan and heat on medium-high heat until it begins to shimmer. Add all the spinach and 1/4 teaspoon of salt. Reduce the heat to medium and stir continuously until the spinach is completely wilted and the liquid is evaporated. Remove the pan from the heat, add the ground nutmeg and stir it into the spinach. Scrape the spinach onto a paper-towel lined plate to absorb any remaining moisture.

Add the butter to the same pan and heat on medium heat until it is melted and starts to bubble. Add the leeks and reduce the heat to medium or medium low. Add 1/4 teaspoon of salt and cook the leeks for 5-7 minutes (stirring occasionally) until the leeks are soft and wilted. If they start to brown, reduce the heat. Add the chopped garlic and cook for another 2 minutes. Remove the pan from the heat, zest the lemon onto the leeks and stir it in.

The oven should be at 350°F.

In a medium bowl whisk the eggs. Add the milk, heavy cream, and parmesan cheese and whisk to combine. Add 1/4 teaspoon of salt and 1/4 teaspoon of fresh ground pepper.

Chop the cooked spinach and spread it evenly over the bottom of the par-baked pie crust. Spread the cooked leeks on top of the spinach. Sprinkle the gruyere cheese over the spinach and leeks. Pour the egg and milk mixture over the cheese and vegetables.

After the quiche has cooled to room temperature, wrap the quiche tightly with plastic wrap or cover the pie plate with foil and refrigerate for up to 4 days.