Lemonade Meringue Pie

1 (9-inch) baked pie shell
1 cup dairy sour cream
3 slightly beaten egg yolks
1 small box regular vanilla pudding mix
1 1/4 cups milk
1/3 cup frozen lemonade concentrate, thawed

Combine sour cream and egg yolk. Stir in pudding mix, milk and lemonade. Cook until it thickens and boils. Remove from heat. Spoon into pie shell. Top hot filling with meringue made with egg whites, spreading meringue to edges to seal. Bake at 350 degrees F for 12 to 15 minutes to brown meringue.