In a medium saucepan, whisk together sugar and cornstarch.
Gradually stir in water until smooth.
Cook over medium heat, stirring constantly until thick and bubbly—about 5 minutes.
Remove from heat and stir in the gelatin until fully dissolved.
Let the mixture cool slightly, about 10 minutes.
Arrange fresh strawberries in the baked pie crust, cut side down for that classic look.
Pour the cooled gelatin mixture evenly over the berries.
Refrigerate until set, at least 3 hours. Slice and serve chilled with whipped cream, if you like!