1919 - The Italian Cook Book

Yellow Sauce

DDV CULINARY

This sauce is especially good for boiled fish, and the quantities indicated
below are sufficient for a piece of fish or a whole fish weighing about a pound.

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.
Let it cool and then pour over the fish that is to be served with a sprig of parsley.

This sauce must have the appearance of a cream and must not be too liquid,
in order that it may remain attached to the fish.