Please make this. You will love it. Your guests will love it. There is a reason I make two...
makes two 13x4-inch tarts
1 3/4 cups all-purpose flour
3/4 cup solid vegetable shortening
1/4 cup ice water
1/4 cup olive oil
4 cups sliced leeks (1/4-inch pieces) (white and pale green parts only)
1 1/2 teaspoons salt
1/2 teaspoon freshly ground black pepper
1/2 pound bacon, coarsely chopped
3 tablespoons unsalted butter
3 tablespoons all-purpose flour
2 cups whole milk
1/4 teaspoon white pepper
1/2 cup coarsely grated Gruyere (5 ounces)
2 large eggs, beaten, at room temperature
Preheat the oven to 375 degrees
To make the crust:
Place the flour in a large bowl, and using a pastry blender, cut in the shortening until the pieces are pea-size. Sprinkle the ice water by tablespoons over the flour mixture, and toss with a fork until all of the dough is moistened. Gather the dough into a ball, and then split the dough in half. Roll the first half out onto a lightly floured surface ( I like to use a piece of wax paper ) to fit a 13x4- inch tart pan. Fit the dough into just the bottom of the tart pan and prick all over the crust with a fork. Repeat with the second half of the dough. Place both tart pans on a baking sheet and bake for 20 minutes. Remove from the oven and set aside to cool.
To make the filling:
Heat the oil in a large skillet over medium heat. Add the leeks, and cook, stirring occasionally, until very tender, 8-10 minutes. Remove from the skillet and set aside. In the same skillet, over medium-low heat, cook the bacon, stirring occasionally, until browned but not too crispy, 10-12 minutes. Remove from the skillet and set aside with the leeks.
Melt the butter in a large saucepan over medium-high heat. When the butter is completely melted and bubbly, add the flour, whisking until well blended, 2-3 minutes. Gradually whisk in the milk. Cover, reduce the heat to medium-low, and cook, whisking occasionally, until the sauce is smooth and thickened, 8-10 minutes. Add the remaining 1/2 teaspoon of salt and the white pepper. Remove from the heat and allow to cool for 10 minutes before stirring in the reserved leeks and bacon, the eggs, and half of the cheese.
Transfer the filling into the tart shells and sprinkle the remaining cheese over the tops. Bake for 30 minutes, until lightly golden and the filling is set. Serve hot.