Bake pie crust as directed or make a homemade pie crust.
Combine the prepared strawberries and sugar in a bowl. Let the berry–sugar mixture sit at room temperature until the strawberries soften, the sugar has completely dissolved, and the mixture has produced about 3/4 cup of strawberry juice, about 20 minutes. Strain the liquid from the strawberries into a measuring cup and add water as needed to reach 1 cup of liquid. Set the strawberries aside.
Whisk the cornstarch into the liquid and transfer to a small pot with about ¼ cup of the strawberries. Use a potato masher or spatula to break the strawberries into small pieces. Heat the mixture over medium-high heat and stir constantly for about 8–10 minutes until it thickens to a jam-like consistency.
Pour the thickened strawberry sauce over the remaining strawberries and toss gently to combine. Spoon the strawberry mixture into the prepared pie crust and flatten the berries with a spatula. Spoon the strawberry mixture into your prepared pie crust and flatten the berries with a spatula. Refrigerate for at least 4 hours or until completely set.
Notes
Storage: Cover leftover strawberry pie with plastic wrap or foil and refrigerate for up to 2 days.