White wine pastry dough
1 3/4 cups all-purpose flour
1/2 tsp. salt
8 tbsp. (1 stick) unsalted butter, cut into small cubes
1 large egg yolk
3 tbsp. dry white wine, dry white vermouth or cold water, plus more if needed
Pancetta and fennel tart filling
1 tbsp. unsalted butter
8 oz. pancetta, diced
1 medium fennel bulb, trimmed, halved, cored and thinly sliced
3/4 tsp. fennel seeds
Salt and freshly ground black pepper, to taste
2 large eggs
1 cup heavy cream
To make pastry dough: In the bowl of a food processor, pulse flour and salt together to combine. Add butter and pulse until mixture resembles coarse sand. Add egg yolk and wine. Continue to process until dough barely comes together. Remove to a lightly floured surface. Shape into a disk and wrap loosely in plastic wrap. Chill until firm, at least 30 minutes. Dough may be refrigerated up to 2 days, or it can be frozen. This makes a 9 1/2-inch tart shell.
To partially bake tart shell: Butter or grease a 9 1/2-inch tart pan with a removable base. On a lightly floured surface, using a lightly floured rolling pin, roll out dough until it is 2 inches larger than the pan. Transfer dough to prepared pan and press it well into the corners, taking care not to stretch it. With your fingers, press dough evenly up the sides of the pan and trim. Prick base of shell with a fork. Chill shell until very firm, 15 to 30 minutes; for quick results, place in the freezer.
Preheat oven to 425 degrees and set a baking sheet lined with parchment paper or a silicone baking mat on a low rack to heat.
Crumple a piece of parchment paper and press it into the tart shell, gently pushing down into the corners. Fill with dry beans or rice to hold the base flat. Bake shell on preheated baking sheet until dough is brown around the edges and firm enough to hold its shape, about 15 minutes. Remove baking sheet and tart pan from oven and lift out parchment and beans. Lower oven to 375 degrees, return tart pan on the baking sheet to the oven and continue baking until the bottom of the pastry is dry, 5 to 10 minutes more. Remove and set aside on a cooling rack while you prepare the filling. Leave the oven on.
To make filling: Melt butter in a large skillet over medium heat and sauté pancetta, stirring often, until lightly browned, 5 to 7 minutes. Stir in fennel, fennel seeds and salt and pepper to taste. Cover and cook over low heat, stirring often, so fennel softens and cooks in its own juices, until it is very tender and lightly browned, 15 to 20 minutes. Spread filling in the tart shell.
Whisk together eggs and cream in a bowl. Season to taste with salt and pepper. Pour egg mixture into tart shell. Bake until filling is set and lightly browned, 30 to 35 minutes. Let sit for at least 20 minutes before serving. Serve warm or at room temperature.
Serves 6 to 8