1 (8 ounce) container frozen pie filling
1/4 cup white sugar
4 tablespoons lemon juice
Preheat oven to 425 degrees F (220 degrees C).
In a small bowl, combine sugar, lemon juice and the egg yolk. Mix just until fluffy and pour mixture into pastry shell.
Bake in preheated oven for 6 minutes. Reduce temperature to 325 degrees F (165 degrees C) and bake for an additional 25 to 30 minutes or until yolks separate from mixture. Chill before serving.