1 (8 oz.) carton commercial sour cream
4 eggs, separated
1 (4 3/4 oz.) pkg. vanilla pudding mix
1 1/3 c. milk
1 (6 oz.) can frozen lemonade concentrate (thawed & undiluted)
1/3 c. sugar
2 tbsp. cornstarch
2 tbsp. water
1/4 c. fresh lemon juice
1 baked 9" deep dish pastry shell
1/2 tsp. cream of tartar
1/2 c. sugar

Combine sour cream and egg yolks in a medium saucepan; mixing well. Stir in pudding mix, milk, lemonade concentrate and 1/3 cup sugar. Combine cornstarch and 2 tablespoons water, mixing well; add to lemon mixture. Cook mixture over medium heat stirring constantly until thickened. Remove from heat and stir in lemon juice. Pour filling into pastry shell.

Combine egg whites (at room temperature) and cream of tartar. Beat until foamy. Gradually add 1/2 cup sugar, 1 tablespoon at a time. Beat until stiff peaks form. Spread meringue over lemon filling, sealing edge of pastry. Bake at 350 degrees for 12-15 minutes or until brown.