The Boston cooking-school cook book

by Fannie Merritt Farmer

Lemon Filling

1 cup sugar

2½ tablespoons flour

Grated rind 2 lemons

¼ cup lemon juice

1 egg

1 teaspoon butter

Mix sugar and flour, add grated rind, lemon juice, and egg slightly beaten. Put butter in saucepan; when melted, add mixture, and stir constantly until boiling-point is reached. Care must be taken that mixture does not adhere to bottom of saucepan. Cool before spreading.