Preheat your oven to 375°F (190°C). Roll out your pie dough on a lightly floured surface, then carefully press it into a 9-inch pie pan. To prevent bubbling, cover the crust with foil and fill it with pie weights, then bake for 30 minutes. Once done, remove the weights and foil, lower the temperature to 350°F (175°C), and dock the crust with a fork. Bake for an additional 15-20 minutes until the crust is lightly golden.

While the crust is baking, zest the lemons directly into a medium saucepan. Juice the lemons until you have about ¾ cup plus 2 tablespoons of juice, then add that and the sugar to the pot. Whisk in the eggs and a pinch of salt, then cook over medium-low heat. Stir continuously until the mixture thickens and reaches 160°F (71°C). Once thickened, strain the filling through a sieve over a bowl containing the butter to create a smooth mixture, then mix in water and tapioca starch until fully combined.

Pour the lemon filling into the baked pie crust, smoothing it out evenly. Bake at 350°F (175°C) for 15-20 minutes, just until the filling is set but still slightly jiggly in the center. Once baked, remove it from the oven and allow it to chill in the refrigerator for a few hours, which helps the filling fully set and enhances its flavors.

In a heatproof bowl set over a pot of simmering water, whisk together the egg whites and the sugar until the sugar dissolves completely. Continue whisking until the mixture is warm to the touch, then transfer it to a stand mixer. Whip on high speed until stiff peaks form. Add the cream of tartar, vanilla extract, and salt, whipping just until combined and glossy for your Lemon Meringue Pie.

Once the lemon filling has chilled and set, spread the meringue over the pie, creating decorative swirls and peaks to encourage browning. Using a kitchen torch or under a broiler set to low, toast the meringue until it turns golden brown—keep a close eye to avoid burning. Serve the pie immediately for the best texture and enjoy the balance of flavors in your delicious Lemon Meringue Pie!