1. Prepare the Crust:
In a large bowl, mix the flour and salt. Add cold butter and use a pastry cutter or fork to cut the butter into the flour until the mixture resembles coarse crumbs.
Slowly add ice water, one tablespoon at a time, until the dough starts to come together.
Form the dough into a disk, wrap it in plastic wrap, and refrigerate for at least 30 minutes.
Preheat your oven to 375°F (190°C). Roll out the chilled dough on a floured surface and fit it into a 9-inch pie dish.
Trim the edges and flute them if desired. Poke the crust with a fork to prevent puffing, and bake for 12-15 minutes, or until lightly golden. Let it cool.
2. Make the Lemon Filling:
In a medium saucepan, whisk together sugar, cornstarch, and salt. Gradually stir in water.
Cook over medium heat, stirring constantly, until the mixture thickens and comes to a boil. Boil for 1 minute, then remove from heat.
Whisk the egg yolks in a separate bowl, then gradually whisk in a small amount of the hot mixture to temper the eggs.
Pour the tempered egg mixture back into the saucepan, whisking continuously. Return to heat and cook for another 2 minutes.
Remove from heat, stir in lemon juice, lemon zest, and butter until smooth.
Pour the filling into the baked pie crust.
3. Prepare the Meringue:
