Bake your premade crust. In a small bowl, combine the cornstarch and 1/3 cup cold water stir to dissolve lumps set aside.
In a medium saucepan combine chopped strawberries sugar and salt. Stir to combine and cook over medium heat until mixture comes to a gentle boil. Cook about 5 minutes until the berries create a little pool of sauce. Stir up the cornstarch and water mixture and add to the pan cook and stir often until the strawberry sauce boils again and thickens up about 4 or 5 minutes. Remove from heat and stir in the butter and vanilla. Set aside to cool to room temperatuare. Beat the heavy cream in a large bowl until very thick. Stir in gently the strawberry mixture and pile into the prepared cooled pie crust. Refrigerate 3 to 4 hours. This can be made with a graham cracker crust if you desire. If fresh strawberries are available I slice and serve the pie on top of them just to make it look pretty. Enjoy.