- In a saucepan combine sugar, cornstarch and salt; add blueberries.
- Turn the heat to medium high and mash together the berries and other ingredients using a potato masher. Make sure the cornstarch is not lumpy. Stir continuously until the filling begins to thicken.
- Set the heat to low and allow to simmer for 5-10 minutes, then add lemon juice and stir together. Remove from heat and allow to cool.