Fillings for Tarts

Three fillings are most often used for lining the bottom of a prebaked pastry shell: pastry cream, crème mousseline, and lemon curd. Pastry cream, which is essentially milk and eggs sweetened with sugar and thickened with cornstarch, is also the classic filling for chocolate éclairs and for many layer cakes. Mousseline, made by beating a large amount of butter into pastry cream, is also a popular filling for layer cakes and some pastries, and it too appears in the chapter on cakes. Lemon curd, which follows here, is made by cooking together eggs, sugar, and lemon juice until the mixture thickens. Sometimes butter is added to give the curd more flavor and so that is it thicker when it cools. Other fruit juices and purees can be used in the same way to make a curd for lining pastry shells, but you can turn to other sources for those once you have mastered the basics. Frangipane, which also follows here, is the most popular choice for lining unbaked pastry shells.