Fresh Blueberry Pie

I wanted to make a pie for Jer for father's day, and we had blueberries in the house, so I decided to go with a fresh blueberry pie.  This is my Gramma's recipe.

Fresh Blueberry Pie

1 cup sugar
3 T cornstarch
1 T lemon juice
1/2 cup water
1 T butter
4 cup blueberries
1 pie crust - baked

Bake single pie crust according to box directions.  In a saucepan, combine sugar, cornstarch, lemon juice, and water. Smash 1 cup of the blueberries into the sauce and cook on medium heat, stirring constantly, until mixture is thick and clear  Add 1 T of butter and stir until it melts in. Fold in remaining blueberries, pour into pie crust, and refrigerate to set.