The crust is a pâte sucré, a sweet short dough that is extremely rich, and can be a pain in the neck to work with. Since the weather is blazing hot here at the moment, I had to keep putting my dough back into the refrigerator to firm up, since if the dough gets soft, it's almost impossible to roll out without it sticking to everything. It can, however, be patched without too much trouble, so if your pastry tears while you're putting it in the tart pan, just press it back together and don't worry about it.

In the book, the recipe says that it will take about 20 minutes for the curd to get thick. My curd took about half that time, and interestingly, the version of this recipe that appears on the Food Network's website says to cook the curd for 10 minutes. I wonder if the Food Network had to change the time estimate after comments from viewers? Another change which I had to make, but which isn't reflected on the Food Network's site, is that the crust needed longer than 5 to 10 minutes to get golden brown after its initial 20 to 25 minutes in the oven. I suspect that Puck uses a restaurant-grade convection oven, which could easily get the pastry deeply golden in only 5 minutes. In my home oven, however, I needed close to 15 minutes for the pastry to get completely browned. You don't want to rush this step, since the pastry does not get cooked again. For a crisp crust, cook it until it is deeply golden.

The recipe says to chill the tart for 3 to 4 hours, or overnight, before serving. I found that the texture of the filling was still way too soft after only 4 hours, and I strongly recommend that you let the tart chill overnight before serving. I've added that recommendation to the recipe.

Caramelizing the top of the tart takes a bit of time if you're using a small crème brûlée torch, and it could deplete your fuel pretty quickly. If you decide to caramelize the sugar under the broiler, watch very carefully, since the edges of the pastry could burn in an instant. The caramelized sugar does make it...interesting to cut the tart into serving pieces. The sugar doesn't necessarily break where you want it to. If the look of the slices is really important to you, you may want to cut the tart into wedges first, and then caramelize the top of each piece individually. That's the only way to guarantee that you don't have broken shards of glassy sugar on top of each slice.

Puck notes that the tart should be refrigerated for 30 minutes after the sugar is caramelized, but he fails to note that you shouldn't keep the tart in the refrigerator for more than an hour after the topping is caramelized, since the nice crisp sugar will become flabby and soft. I've added this note to the recipe.

Prep Time: about 1 hour, plus 1 hour chilling time for the pastry
Cook Time: about 30 minutes
Yield: 8 to 10 servings

Pâte Sucré
1 1/4 cups cake or pastry flour
4 Tbsp granulated sugar
1/4 pound unsalted butter, chilled and cut into small pieces
1 large egg yolk
1 to 2 Tbsp heavy cream

Lemon-Lime Filling
4 large eggs
4 large egg yolks
1 cup plus 2 Tbsp granulated sugar
2/3 cup fresh lime juice
2/3 cup fresh lemon juice
Zest of 2 small limes
Zest of 2 small lemons
6 oz. butter, softened and cut into pieces
Fresh raspberries or strawberries, for serving (optional)

For the pastry: In a food processor fitted with the steel blade, combine the flour and sugar. Add the butter and process until the texture resembles fine meal.

In a small bowl, whisk together the yolk and 1 tablespoon of the cream. Scrape into the machine and process until a ball begins to form, using the additional tablespoon of cream, if necessary. Remove the dough from the machine, and on a lightly floured surface, press down into a disk. Wrap in plastic wrap and refrigerate for at least 1 hour.

Preheat the oven to 350 degrees.

Roll out the pâte sucré to a circle about 1/4 inch thick and large enough to slightly overlap a 9-inch metal tart pan. Fit the dough into the pan and trim the edges. Line the bottom and sides of the shell with parchment, or coffee filter papers, or aluminum foil. Fill the lining with dried beans, rice, or aluminum beans or pie weights, and bake in the oven for 20 to 25 minutes. Cool and remove the beans and the lining. Return the shell to the oven and bake until golden, 10 to 15 minutes longer.

In a large metal bowl, whisk together the whole eggs, egg yolks, 1 cup sugar, lemon and lime juice, and zests. Set over simmering water and continue to whisk until the mixture is very thick, about 10 minutes.

Turn off the flame and whisk in the butter, a few pieces at a time. (You don't want the mixture to cool down before all the butter is incorporated.) Strain the filling into a bowl (you'll need to push the curd through the strainer with a rubber spatula). Scrape into the baked tart shell and smooth with a spatula. Cool and then refrigerate until firm, at least 4 hours, and preferably overnight.

Sprinkle the remaining 2 tablespoons of sugar evenly over the top of the filling. With a propane blowtorch, caramelize the sugar. (This can also be done under the broiler. Place the tart on the broiler tray directly under the flame, watching carefully to prevent burning). Refrigerate the tart for at least 30 minutes, and no longer than 1 hour. Or, if desired, eliminate the 2 tablespoons of sugar and arrange circles of raspberries on top of the tart. Sift a little powdered sugar over the berries just before serving.

Cut into slices and serve. If you have caramelized the sugar, serve the tart with fresh strawberries or raspberries, if desired.