Lemon Blueberry Custard Pie

Bahan-bahan (8 porsi)

• One 9 inch unbaked pie crust
• 1 tablespoon butter, (softened)
• ⅔ cup granulated white sugar
• 2 tablespoons all purpose flour
• 3 tablespoons freshly squeezed lemon juice
• 1 tablespoon grated lemon zest
• 2 large egg yolks
• 1 cup milk
• 2 large egg whites
• 1¼ cups fresh blueberries