Step 1Combine the milk and cream in a large saucepan and heat over medium heat until scalded (meaning a skin begins to form on the surface). Remove from heat and set aside to cool slightly, 10 to 15 minutes.
Step 2Put the eggs, the milk mixture, salt, pepper and nutmeg in a blender and blend on low speed about 5 seconds to mix thoroughly, then increase the speed to high and blend until the batter is light and foamy, about 30 seconds. Immediately pour into the hot quiche shell and bake.
Step 1Place 1 cup of the flour and the salt in the bowl of a heavy-duty mixer fitted with the paddle attachment. Turn the mixer to low speed and add the butter a small handful at a time.
Step 2When all the butter has been added, increase the speed to medium and mix until the butter is completely blended with the flour. Reduce the speed, add the remaining flour and mix just to combine.
Step 3Add the water a little at a time and mix until the dough gathers around the paddle and pulls cleanly away from the sides of the bowl. It should feel smooth, not sticky.
Step 4Remove the dough from the mixer and check to be certain that there are no visible pieces of butter remaining; if necessary, return the dough to the mixer and mix briefly again. Pat the dough into a 7- to 8-inch disk and wrap in plastic. Refrigerate for at least 1 hour or up to a day. (If the dough does not rest, it will shrink as it bakes.)
Step 5Lightly brush the inside of a 9-by-2-inch removable-bottom tart pan with canola oil and place it on a jelly roll pan. Place the dough on a floured work surface and rub on all sides with flour. Flatten it into a larger circle using a rolling pin or the heel of your hand. Roll the rolling pin back and forth across the dough a few times, then turn it 90 degrees and roll again. Continue to turn and roll until the dough is one-fourth inch thick and about 14 inches in diameter. (If the kitchen is hot and the dough has become very soft, move it to a baking sheet and refrigerate for a few minutes.)
Step 6To lift the dough into the tart pan, place the rolling pin across the dough about one-quarter of the way up from the bottom edge, fold the bottom edge of the dough up and over the pin, and roll the dough up on the rolling pin. Lift the dough on the pin and hold it over the pan, centering it. Carefully lower the dough into the pan, pressing it gently against the sides and into the bottom. Trim any dough that extends more than an inch over the sides of the pan and reserve the scraps. Fold the excess dough over against the outside of the ring. (Preparing the quiche shell this way will prevent it from shrinking down the sides as it bakes. The excess dough will be removed after the quiche is baked.) Carefully check for any cracks or holes in the dough, and patch with the reserved dough as necessary. Place in the refrigerator or freezer for at least 20 minutes to resolidify the butter. Reserve the remaining dough scraps.
Step 7Place a rack in the middle of the oven and heat the oven to 375 degrees. Line the quiche shell with a 15-inch round of parchment paper. Fill the shell with pie weights or dried beans, gently guiding the weights into the corners of the shell and filling the shell completely. Bake the shell until the edges of the dough are lightly browned but the bottom is still light in color, 35 to 45 minutes.
Step 8Carefully remove the parchment and weights. Check the dough for any new cracks or holes and patch with thin pieces of the reserved dough if necessary. Return the shell to the oven until the bottom is a rich golden brown, 15 to 20 minutes. Remove from the oven and allow the shell to cool completely on the jellyroll pan. Once again, check the dough for any cracks or holes, and patch if necessary before filling with the quiche batter.
Step 1Cut off the dark green leaves from the leeks and discard. Cut off and discard the root end and bottom 1 inch of each leek. Cut the leeks lengthwise in half and wash well under cold running water. Place cut side down on a cutting board and slice crosswise into 1/4 -inch-thick slices. (You should have 4 to 5 cups packed leeks.)
Step 2Bring a large pot of salted water to a boil. Add the leeks and cook for about 5 minutes, or until tender. Drain the leeks and spread them on a baking sheet to cool. Place a rack in the center of the oven and heat the oven to 325 degrees.
Step 3Squeeze the cooled leeks to remove excess water and dry on paper towels. Scatter half the chopped leeks and half the Roquefort evenly into the hot quiche shell (still on the jelly roll pan).
Step 4Blend the quiche batter again to aerate it, then pour in enough of the batter to cover the ingredients and fill the quiche shell approximately halfway. Top the batter with the remaining leeks and cheese. Blend the remaining batter once more and fill the quiche shell all the way to the top (if you don't have a very steady hand, you might spill some of the batter on the way to the oven; fill the shell most of the way, then pour the final amount of batter on top once the quiche is on the oven rack). You may have some batter left over. Bake for 5 minutes. The filling level will drop. Pour in the remaining batter to fill to the top; there may be a little left over.
Step 5Bake for 1 hour, 15 minutes, until the top of the quiche is browned and the custard is set when the pan is jiggled. Remove the quiche from the oven and let stand 15 minutes before serving, or cool, then refrigerate until chilled, at least 1 day, or up to 3 days.
Step 6Once the quiche is thoroughly chilled, using a metal bench scraper or a sharp knife, scrape away the excess crust from the top edge. Place a large bowl upside down on a work surface and place the quiche pan on top of that. Gently remove the outside ring, working it free in spots with a small knife if necessary. Return to the refrigerator until ready to serve.
Step 7To serve, heat the oven to 375 degrees. Line a baking sheet with lightly oiled parchment paper. Using a long serrated knife, and supporting the sides of the crust with your opposite hand, carefully cut through the edge of the crust in a sawing motion. Switch to a long slicing knife and cut through the custard and bottom crust. Repeat, cutting the quiche into 8 to 10 pieces. Place the pieces on the baking sheet and reheat for 15 minutes or until hot throughout. To check, insert a metal skewer into the quiche for several seconds and then touch the skewer to your lip to test the temperature of the quiche.