I had enough pine nut crust dough from making Thomas Keller's lemon tart to make one more tart, so I figured I would make one more lemon tart for comparison. Tartine's lemon cream recipe had caught my eye a while back so I decided to try that as the filling. Comparing the three recipes, this one has almost the same ratio of ingredients as Keller's except it has twice the amount of butter. And it's a little easier than Keller's because it uses Lazy Mary's method of using a blender to incorporate the butter instead of doing it over a steaming hot pot of water.
Lemon Cream Tart (from Tartine)
makes 1 tart
1/2 cup + 2 tablespoons lemon juice (Meyer or regular, I used regular)
3 large eggs
1 large egg yolk
3/4 cup sugar
Pinch of salt
1 cup (2 sticks) unsalted butter
1 pre-baked tart shell at room temperature (I used Thomas Keller's pine nut crust)
Pour water to a depth of about 2 inches into a saucepan, place over medium heat, and bring to a simmer.
Combine the lemon juice, whole eggs, yolk, sugar, and salt in a stainless steel bowl that will rest securely in the rim of a saucepan over, not touching, the water. (Never let the egg yolks and sugar sit together for more than a moment without stirring; the sugar will cook the yolks and turn them granular.)
Place the bowl over the saucepan and continue to whisk until the mixture becomes very thick and registers 180° F on a thermometer. This will take 10 to 12 minutes. If you don't have or trust your thermometer, don't worry. It should thicken to the point that your whisk leaves a trail through the curd.
Remove the bowl from over the water and let cool to 140° F, stirring from time to time to release the heat.
Meanwhile, cut butter into 1-tablespoon pieces. When the cream is ready, leave it in the bowl if using an immersion blender, or pour it into a countertop blender. With the blender running, add the butter 1 tablespoon at a time, blending after each addition until incorporated before adding the next piece. The cream will be pale yellow and opaque and quite thick.
Pour the cream into your pre-baked tart shell and cover with plastic wrap. Cool to room temperature and then place in the refrigerator to chill for several hours.
Out of the three, this was definitely my favorite lemon tart. The lemon cream was a perfect balance of sweet and sour, of acidity and creaminess. I was afraid that it wouldn't set enough to cut into slices, but after a few hours in the fridge, it was actually firm enough to cut.
I was lucky enough to go to Tartine recently for my birthday and try an authentic Tartine lemon cream tart. They didn't use a pine nut crust, but other than that, I'd say that it tasted pretty much exactly the same as the one this recipe makes!