Creating a Lemon Meringue Pie involves precise steps:

For the Pie Crust

1. Preheat Oven: Begin by preheating your oven to 350°F (175°C).
2. Combine Dry Ingredients: In a mixing bowl, whisk together flour and sugar.
3. Cut in Butter: Add the diced butter, mixing until the mixture resembles coarse crumbs.
4. Add Egg Yolk: Mix in the egg yolk and combine well.
5. Add Ice Water: Gradually stir in ice water, just enough to form a ball.
6. Roll Out Dough: On a floured surface, roll out the pastry to fit a 9-inch pie pan.
7. Fit to Pie Pan: Place the rolled-out dough in the pie pan and trim to fit. Prick the bottom with a fork.
8. Pre-Bake Crust: Place a piece of parchment paper over the crust and fill it with pie weights. Bake for 15 minutes, then remove the weights and parchment, and bake for an additional 5 minutes until golden. Set aside.

For the Lemon Filling

9. Mix Dry Ingredients: In a saucepan, combine the sugar, cornstarch, and salt.
10. Add Wet Ingredients: Gradually whisk in water, then add beaten egg yolks.
11. Cook the Filling: Cook over medium heat while stirring until the mixture thickens and bubbles. Once boiling, stir for an additional 1-2 minutes.
12. Add Butter and Lemon: Remove from heat, stir in butter, lemon juice, and lemon zest. Mix well.
13. Pour into Crust: Pour the lemon filling into the pre-baked pie crust.

For the Meringue

14. Beat Egg Whites: In a clean bowl, beat egg whites and cream of tartar until soft peaks form.
15. Gradually Add Sugar: Slowly add sugar, continuing to beat until stiff peaks form and glossy.
16. Add Vanilla: Mix in the vanilla extract.
17. Spread Meringue: Carefully spread meringue over the lemon filling, ensuring it touches the crust edges to seal.
18. Bake: Bake in the preheated oven for 10-12 minutes, or until golden brown.
19. Cool: Allow the pie to cool at room temperature for at least 1 hour before slicing.