4 c. fresh or frozen blueberries
1 c. sugar
3 tbsp. cornstarch
1/4 tsp. salt
1/4 c. water
1 tbsp. butter

Line a 9 inch baked pie shell with 2 cups blueberries. To make sauce, cook blueberries with the sugar, cornstarch, salt and butter. Cook over medium heat and remove from heat; add butter and cool. Pour over berries in shell. Chill until serving time. If desired, serve with Cool Whip.