Local And Seasonal: Walnut Tart With Chocolate Cream
Walnuts are native to the mountain ranges of Central Asia, where nut-bearing trees have grown since ancient times. Alexander the Great is said to have carried walnuts throughout his vast empire, spreading the seeds from modern-day Kyrgyzstan to the Ionian Sea. Romans introduced cultivated varieties of Juglans regia, the common walnut, to Northern Africa, and in the 17th century British sailors brought them to America. Today, China produces more walnuts than any other country, but California leads the way among U.S. states, growing ninety-nine percent of our domestic crop.
There's no better time to enjoy walnuts than autumn, when the nuts are freshly harvested. It's worth seeking out these new crop walnuts in farmers' markets, at roadside stands, or anywhere you can be sure the nuts are just picked. They should taste moist, creamy, and exceptionally sweet. Walnuts are rich in alpha-lenolenic acid, an essential omega-3 polyunsaturated fatty acid found to lower the risk of cardiovascular disease.
Walnuts spoil quickly because of the abundance of this nutritious oil. It's best to store them in a cool place, sealed in an airtight container. The refrigerator is a great spot for keeping walnuts fresh, and the freezer is even better, especially if you don't plan to eat them for a few months. Whole nuts, still in their shells, can be stored at room temperature.
During the holidays, we often keep a wide, shallow bowl of walnuts on the table with a nutcracker nearby. Once pried from their shells, the nuts are that much closer to becoming this festive tart.
Walnut Tart with Chocolate Cream
You can make this sweet, creamy tart in a pan of any shape and size, depending on how thick you prefer your crust. There is no need to roll out the dough--simply press it directly into the pan. A tart pan with a removable bottom makes for an easy and beautiful scalloped edge. Sometimes I adorn the finished tart with a handful of raspberries.
Serves 8
5 ounces shelled walnuts (about 1 1/3 cups)
½ cup granulated sugar
1¼ cups plus 1 tablespoon all-purpose flour
8 tablespoons (1 stick) unsalted butter, chilled and cut into 8 pieces
¼ teaspoon Kosher salt
2 cups half-and-half
3 large egg yolks
1 tablespoon cornstarch
3½ ounces semi-sweet chocolate, broken into small pieces
½ teaspoon pure vanilla extract
Preheat the oven to 350ºF.
Place the walnuts and ¼ cup sugar in the bowl of a food processor fitted with a metal blade. Pulse several times to break up the walnuts into small pieces. Add 1¼ cups flour, the butter, and salt. Pulse a few more times. Drizzle 4 teaspoons cold water evenly over the flour mixture, then pulse until the dough just comes together in a ball. Transfer the dough to a 9-inch tart pan with a removable bottom. Using your fingers or a rubber spatula, press the dough evenly across the bottom and up the sides of the pan. Bake for 30 minutes, or until lightly golden brown around the edges. Let the tart crust cool to room temperature.
Meanwhile, warm the half-and-half in a heavy-bottomed saucepan over medium heat. As soon as the half-and-half simmers, remove it from the heat. In a large bowl, whisk together the egg yolks, cornstarch, remaining tablespoon flour, and remaining ¼ cup sugar. While whisking, slowly pour ½ cup of the warm half-and-half into the egg mixture. Once combined, pour this egg-half-and-half mixture back into the saucepan. Cook over low heat, whisking constantly, for 3 minutes, or until thickened. Remove the pastry cream from the heat, and stir in chocolate, vanilla, and a pinch of salt.
When the crust has cooled, pour the chocolate cream filling into it and smooth the top with a rubber spatula. Lay a sheet of plastic wrap directly onto the chocolate cream filling, and chill tart in the refrigerator until cool, about 2 hours.