In a bowl, mix together flour, cornstarch, salt, eggs, and vanilla flavor until a smooth mixture forms.
In a saucepan, heat milk and sugar until just simmering, stirring occasionally to prevent milk from scorching on the bottom of the pan. While whisking the egg mixture constantly, slowly pour 1 cup of warm milk into the egg mixture. Whisk until smooth. This will help gently heat the eggs and prevent them from curdling in the next step.
As milk starts to boil in the pan, begin whisking milk quickly and carefully pour egg mixture into saucepan. The heat will begin to thicken the mixture. As custard starts to thicken, turn heat down and continue whisking, 3-5 minutes.
Set custard aside to cool. Cover with plastic wrap and refrigerate. Clean strawberries and pour a 1/2 cup or more strawberry glaze in a bowl and then add the cleaned berries and mix to coat well. When custard is cooled, pour into pie crust. Slice glazed berries and place on top of custard covering completely. Top with whipped cream if you like. Makes 1 pie. Enjoy!