Buttermilk Lemon Pie recipe.

Ingredients
1 cup sugar
1/2 cup all-purpose flour
2 cups buttermilk
1/2 cup water
3 egg yolks, lightly beaten
6 tablespoons lemon juice
2 tablespoons butter or margarine
3 egg whites
6 tablespoons sugar
1 (9 inch) pastry shell, baked

Directions
In a large saucepan, combine sugar and flour. Gradually stir in buttermilk and water until smooth. Cook and stir over medium heat until thickened and bubbly, about 4 minutes. Reduce heat; cook and stir 2 minutes longer. Remove from the heat.
Stir in a small amount of hot filling into egg yolks; return all to the pan, stirring constantly. Bring to a gentle boil; cook and stir 2 minutes longer. Remove from the heat; stir in lemon juice and butter until butter is melted. Keep warm.
In a small mixing bowl, beat the egg whites on medium speed until soft peaks form. Gradually beat in sugar, 1 tablespoon at a time, on high just until stiff peaks form and sugar is dissolved.
Pour the hot filling into pastry shell. Spread meringue evenly over hot filling, sealing edges to crust. Bake at 350 degrees F for 15 minutes or until the meringue is golden brown. Cool on a wire rack for 1 hour; refrigerate for at least 5 hours before serving. Refrigerate leftovers.