4 eggs, separated, 2 tablespoons flour, 1 cup sugar, 1/4 cup unsalted butter, melted and cooled, 2 cups buttermilk, 1 teaspoon lemon extract, 1 tablespoon fresh lemon juice, 1/8 teaspoon salt, 1 (9-inch) unbaked pie crust, 1 1/2 teaspoon nutmeg.
Preheat the oven to 450 degrees. In a large bowl add the egg yolks, flour, sugar, buttermilk, lemon juice, butter, and extract. Mix well. In a separate bowl add the egg whites and beat until they are stiff. Fold the whites into the batter. Pour the batter into the pie crust. Bake for 10-12 minutes. Reduce the temperature to 300 degrees; bake for another 35 minutes or until the center of the pie is firm.