for the filling
2 tablespoons (1/4 stick) butter
2 cups chopped leeks (white and pale green parts only)
1/4 cup chopped fresh parsley
6 slices bacon, cut into 1/2-inch pieces
3 large eggs
2/3 cup whipping cream
2/3 cup crème fraîche
1/4 teaspoon salt
1/4 teaspoon pepper
1/8 teaspoon ground nutmeg
Make the Pie crust: Whisk the flour and salt together in a medium size bowl. Cut in the cold shortening until the mixture resembles coarse crumbs. Drizzle 2 to 3 tablespoons ice water over flour. Toss mixture with a fork to moisten, adding more water a few drops at a time until the dough comes together. Gently gather dough particles together into a ball. Wrap in plastic wrap, and chill for at least 30 minutes before rolling.
Preheat oven to 425F degrees.
Roll out dough, and put in a 10-inch springform pan. Cover the dough with aluminum foil and gently poke the foil into the side edges to fit the pan. This will help to keep the sides of the tart tall and straight as it cooks. Fill the tart shell with pie weights and place in the preheated oven. Bake for 10 to 12 minutes, remove the foil and weights and bake for 2 to 3 minutes more. Remove the tart shell from the oven and cool. The dough should be golden and crisp. Set aside.
Reduce oven temperature to 400F degrees.
Melt 2 tablespoons butter in heavy medium skillet over medium heat. Add leeks and parsley; sauté until beginning to soften, about 3 minutes. Spoon mixture into crust. Cook bacon in same skillet until crisp. Using slotted spoon, transfer bacon to paper towels and drain. Sprinkle bacon over leeks. Beat eggs, cream, crème fraîche, salt, pepper and nutmeg in small bowl to blend; pour into crust.
Bake pie until filling is set in center, about 30-35 minutes. Remove pan sides. Transfer pie to platter and serve.