For the Pastry Dough:

1. Blend all the ingredients for the pastry dough together and form into a disk.
2. Wrap and chill in the fridge for 30 minutes.
3. Preheat oven to 350 F° (180 C°).
4. Roll the dough out to about ¼-inch thick. Fit into a 9-inch tart shell, score the bottom with a fork, and bake for 20 minutes or until golden. Remove and let cool completely.

For the Lemon Curd:

1. Whisk together egg yolks, sugar, and cornstarch in a small saucepan over medium heat. Add lemon zest and juice, whisking constantly until thickened. Strain through a mesh strainer.
2. Pour the curd into the baked tart shell and let cool to room temperature before transferring to the refrigerator to set until ready to top with meringue.

For the Italian Meringue:

1. Whip egg whites and cream of tartar until soft peaks have formed.
2. In a small saucepan over medium heat, whisk sugar and water to make a simple syrup.
3. Once it has come to a boil and thickened slightly, SLOWLY pour it into the partially beaten egg whites, while the mixer is on medium speed. Keep beating until glossy stiff peaks form.
4. Spoon or pipe the meringue on top of the tart. Using a culinary torch, lightly toast the tips of the meringue. Serve and enjoy!