Maria Gentile, The Italian Cook Book: the Art of Eating Well… (1919)
“ Put on the fire in a little saucepan one teaspoonful of flour and two ounces of butter, and when the flour begins to be browned, pour over it little by little one cup of the broth of the fish, that is to say of the water in which the fish has been boiled. When you see that the flour does not rise in the boiling water, take away the sauce from the flour and pour over two tablespoonfuls of olive oil and the yolk of an egg, stirring and mixing everything well. Squeeze in the sauce half a lemon and season generously with salt and pepper. ”
