1. Prepare the Pie Crust:

1. Make the Dough: In a medium bowl, combine the flour and salt. Add the cold butter cubes and use a pastry cutter or your hands to work the butter into the flour until the mixture resembles coarse crumbs. Gradually add ice water, one tablespoon at a time, until the dough comes together. Be careful not to overwork the dough.
2. Chill the Dough: Wrap the dough in plastic wrap and refrigerate for at least 30 minutes to allow it to firm up.
3. Roll Out the Dough: On a lightly floured surface, roll the chilled dough into a circle about 12 inches in diameter. Gently transfer it into a 9-inch pie dish, trimming any excess dough.
4. Blind Bake the Crust: Preheat the oven to 375°F (190°C). Line the pie crust with parchment paper and fill with pie weights or dried beans. Bake for 15-20 minutes until the crust is lightly golden. Remove the parchment paper and weights, and bake for an additional 5-7 minutes until the bottom is golden and crisp. Let the crust cool while you prepare the filling.

2. Make the Lemon Filling:

1. Combine Dry Ingredients: In a medium saucepan, whisk together the sugar, cornstarch, and salt.
2. Add Wet Ingredients: Slowly whisk in the water and cook over medium heat, stirring constantly until the mixture thickens and starts to boil. Once it reaches a boil, reduce the heat to low and cook for 1-2 minutes to ensure the cornstarch is fully cooked.
3. Temper the Egg Yolks: In a small bowl, whisk the egg yolks. Gradually add a small amount of the hot mixture to the egg yolks while whisking constantly to prevent curdling (this process is called tempering).
4. Combine and Cook: Slowly pour the egg yolk mixture back into the saucepan while whisking constantly. Continue to cook over low heat for 1-2 minutes, until the filling is thick and glossy.
5. Add Lemon Flavor: Remove from heat and stir in the lemon juice, lemon zest, and butter. Mix until the butter is fully melted and incorporated.
6. Cool the Filling: Pour the lemon filling into the prepared pie crust and smooth the top with a spatula. Allow the filling to cool while you prepare the meringue.

3. Make the Meringue:

1. Whip the Egg Whites: In a clean bowl, beat the egg whites and cream of tartar using an electric mixer on medium-high speed until soft peaks form.
2. Add Sugar Gradually: Slowly add the sugar, one tablespoon at a time, continuing to beat until stiff, glossy peaks form and the sugar is fully dissolved. Add the vanilla extract and beat for another 30 seconds to combine.
3. Top the Pie with Meringue: Spoon the meringue over the lemon filling, spreading it out to cover the entire surface and sealing the edges to the crust to prevent shrinking.
4. Bake the Pie: Bake the pie at 350°F (175°C) for 10-15 minutes, or until the meringue is golden brown.

4. Cool and Serve:

1. Cool the Pie: Let the pie cool at room temperature for about 1 hour. Then, refrigerate the pie for at least 2 hours to allow the filling to set.
2. Slice and Serve: Once chilled and set, slice the pie into wedges and serve!