Rinse your strawberries under cool water and pat them completely dry with a clean kitchen towel. Remove the green leafy tops by cutting them out at an angle with a sharp knife, then cut each berry in half lengthwise.

In a small bowl, whisk together the cornstarch, sugar, and salt until evenly combined.

Pour the halved strawberries into a large pot and sprinkle the sugar and cornstarch mixture over them. Gently toss everything together using a wooden spoon or silicone spatula, making sure the dry ingredients coat the berries evenly. Let the mixture sit for 2 to 3 minutes so the strawberries begin releasing their juice.

Place the pot over medium heat and bring the mixture to a gentle simmer, stirring occasionally. Cook for 10 to 12 minutes until the liquid transforms from cloudy to clear as the cornstarch gelatinizes.

Once the filling reaches a gentle simmer and the liquid has thickened, remove the pot from heat and stir in the fresh lemon juice and vanilla extract.

Let the filling cool in the pot for about 5 minutes, stirring gently a few times.

Pour the slightly cooled filling into a pre-baked pie crust slowly and evenly. If your crust is unbaked, brush the bottom with egg white before pouring to create a moisture barrier.

Refrigerate the pie for at least 4 hours, but preferably overnight, until the filling is completely set and firm.