The Most Extraordinary Lemon Cream Tart

With a big silver spoon in hand, I could consume this entire creation in a single sitting. However, being prudent, I choose instead to savour it over several days - each time in awe yet again of the perfection that is this cream. Yes, this is simply one of the most extraordinary concoctions ever. The smooth mouth feel of the butter-laden lemon cream is at once light on the tongue and richly satisfying. It is the definition of the term "luscious", and everyone needs to try it at least once.

Pierre Herme's Most Extraordinary French Lemon Cream Tart

Yield: 8 servings

Adapted from Baking From My Home to Yours, by Dorie Greenspan

Ingredients

1 cup sugar
Finely grated zest of 3 lemons
4 large eggs
3/4 cup freshly squeezed lemon juice (4 to 5 lemons)
2 sticks plus 5 tablespoons (298grams; 21 tablespoons; 10 1/2 ounces) unsalted butter, at room temperature and cut into tablespoon-sized pieces
1 fully-baked 9-inch tart shell (recipe follows)

Procedure

Getting ready: Have a thermometer, preferably an instant-read, a strainer and a blender at the ready. Bring a few inches of water to a gentle boil in a saucepan.

1. Put the sugar and zest in a large metal bowl that can be fitted into the pan of gently boiling water. Off heat, work the sugar and zest together between your fingers until the sugar is moist, grainy and very aromatic. Whisk in the eggs followed by the lemon juice.

2. Fit the bowl into the pan (make certain the water doesn’t touch the bottom of the bowl) and cook, stirring with the whisk as soon as the mixture feels tepid to the touch. You want to cook the cream until it reaches 82°C/180°F. As you whisk the cream over heat—and you must whisk constantly to keep the eggs from scrambling — the cream will start out light and foamy, then the bubbles will get bigger, and then, as the cream is getting closer to 82°C/180°F, it will start to thicken and the whisk will leave tracks. The tracks mean the cream is almost ready. Do not stop whisking and do not stop checking the temperature. And have patience—depending on how much heat you’re giving the cream, getting to temp can take as long as 10 minutes.

3. As soon as you reach 82°C/180°F, pull the cream from the heat and strain it into the container of a blender; discard the zest. Let the cream rest at room temperature, stirring occasionally, until it cools to 60°C/140°F, about 10 minutes.

4. Turn the blender to high and, with the machine going, add about 5 pieces of butter at a time. Scrape down the sides of the container as needed while you are incorporating the butter. Once the butter is in, keep the machine going — to get the perfect light, airy texture of lemon-cream dreams, you must continue to beat the cream for another 3 minutes. If your machine protests and gets a bit too hot, work in 1-minute intervals, giving the machine a little rest between beats.

5. Pour the cream into a container, press a piece of plastic wrap against the surface to create an airtight seal and chill the cream for at least 4 hours or overnight. When you are ready to construct the tart, just whisk the cream to loosen it and spoon it into the tart shell.

Serving: The tart should be served cold, because it is a particular pleasure to have the cold cream melt in your mouth.

Storing: While you can make the lemon cream ahead (it will keep in the fridge for 4 days and in the freezer for up to 2 months), once the tart is constructed, it is best to eat it the day it is made.

Pâte Sucrée

Makes enough for one 9-inch crust.

Storing: Well wrapped, the dough can be kept in the refrigerator for up to 5 days or frozen for up to 2 months. While the fully baked crust can be packed airtight and frozen for up to 2 months, it can be frozen unbaked, and baked directly from the freezer. Just add about 5 minutes to the baking time.

The simplest way to make a tart shell with this dough is to press it into the pan with your fingers.

1 1/2 cups all-purpose flour
1/2 cup confectioners' sugar
1/4 teaspoon salt
1 stick plus 1 tablespoon (9 tablespoons) very cold (or frozen) unsalted butter, cut into small pieces
1 large egg yolk

Put the flour, confectioners' sugar and salt in a food processor and pulse a couple of times to combine. Scatter the pieces of butter over the dry ingredients and pulse until the butter is coarsely cut in—you should have some pieces the size of oatmeal flakes and some the size of peas. Stir the yolk, just to break it up, and add it a little at a time, pulsing after each addition. When the egg is in, process in long pulses—about 10 seconds each—until the dough, which will look granular soon after the egg is added, forms clumps and curds. Just before you reach this stage, the sound of the machine working the dough will change—heads up. Turn the dough out onto a work surface and, very lightly and sparingly, knead the dough just to incorporate any dry ingredients that might have escaped mixing.

To press the dough into the pan: Butter a 9-inch fluted tart pan with a removable bottom. Press the dough evenly over the bottom and up the sides of the pan, using all but one little piece of dough, which you should save in the refrigerator to patch any cracks after the crust is baked. Do not be too heavy-handed—press the crust in so that the edges of the pieces cling to one another, but not so hard that the crust loses its crumbly texture. Freeze the crust for at least 30 minutes, preferably longer, before baking.

To partially or fully bake the crust: Center a rack in the oven and preheat the oven to 375°F. Butter the shiny side of a piece of aluminum foil and fit the foil, buttered side down, tightly against the crust. (Since you froze the crust, you can bake it without weights.) Put the tart pan on a baking sheet and bake the crust for 25 minutes. Carefully remove the foil. If the crust has puffed, press it down gently with the back of a spoon. For a partially baked crust, patch the crust if necessary, then transfer the crust to a cooling rack (keep it in its pan).

To fully bake the crust: Bake for another 8 minutes or so, or until it is firm and golden brown. (I dislike lightly baked crusts, so I often keep the crust in the oven just a little longer. If you do that, just make sure to keep a close eye on the crust's progress—it can go from golden to way too dark in a flash.) Transfer the tart pan to a rack and cool the crust to room temperature before filling.

To patch a partially or fully baked crust, if necessary: If there are any cracks in the baked crust, patch them with some of the reserved raw dough as soon as you remove the foil. Slice off a thin piece of the dough, place it over the crack, moisten the edges and very gently smooth the edges into the baked crust. If the tart will not be baked again with its filling, bake for another 2 minutes or so, just to take the rawness off the patch.