Frolle Paste or Sweet

Arrange one pound of sifted flour in a circle on the table; in the center lay half a pound of butter, half a pound of sugar, the peel of a lemon, chopped very fine, a pinch of salt, one whole egg and four to five yolks. Work the whole well together to obtain a smooth paste, kneading it twice; form into a ball and put aside in the icebox to rest.