Lemon Pie

From 1922:

Line a piedish with a good puff paste, and fill it with the following: The grated rind and juice of a lemon, a large cupful of cold water, three-quarters of a cupful of sugar. Mix these, and let them come to a boil; next add a tablespoonful cornflour, which has been diluted with a little water and the yolk of an egg. Let the paste in the piedish bake by itself, then pour over it the above mixture; spread over the top the beaten white of an egg, sweetened with a spoonful of sugar, and brown for a few minutes.