3/4 c. sugar
3 tbsp. cornstarch
1/4 c. water
4 c. blueberries
1 tbsp. butter
1 tbsp. lemon juice

Combine sugar and cornstarch in saucepan. Add water and 2 cups blueberries. Cook over medium heat stirring constantly until mixture comes to a boil and is thickened and clear.

Remove from heat. Stir in butter and lemon juice. Cool.

Place remaining 2 cups of blueberries in baked pie shell. Top with cooked berry mixture. Chill.