Special equipment: Rolling pin 6 (4-inch) tart molds with removable bottoms 3 cups of pie weights or dried beans Cheese grater
Preheat the oven to 400 degrees F.
For the pastry: Roll the pastry to 1/4-inch thickness and cut into 6 (6-inch) rounds. Place the pastry in 6 (4-inch) tart molds. With a knife trim the excess pastry. Refrigerate for at least 30 minutes.
Line each tart shell with a piece of parchment paper and fill to the rim with pie weights.
Bake for 15 minutes. Reduce the oven temperature to 350 degrees F. Remove the pie weights and parchment from the tart shells and bake for 10 minutes.
For the filling: Whisk together the lemon juice, eggs, yolks, sugar, and vanilla extract.
Pour the lemon mixture into a medium pot. Place over medium heat and stir with a spatula for about 5 minutes, until the mixture begins to thicken. Pour the lemon mixture onto a baking sheet and cool completely.
Spoon the cooled lemon mixture or curd into the baked tart shells.
For the meringue: Beat the egg whites with the vanilla extract and cream of tartar until soft peaks form. Continue beating while adding the sugar, 1 tablespoon at a time. The finished meringue should have stiff glossy peaks. Mound the meringue on top of the tarts.
Make sure there is a good seal between the meringue and the edge of the crust. Bake the tarts in a preheated 350 degree F oven for 20 to 25 minutes, or until the meringue is golden. Let cool for 15 minutes before removing from the molds.
Sift the flour and salt into a large mixing bowl. Using a cheese grater, grate the butter and shortening into the flour. Combine the mixture with your fingers until it resembles cornmeal. Add the ice cold water and mix with a spoon, pulling the water into the flour until a dough forms.
With your hands, shape the dough into 2 balls and flatten them into disks. Wrap the dough in plastic wrap and refrigerate for at least 30 minutes. Store in the refrigerator for up to 4 days and in the freezer for up to 1 month.