Cream of Jerusalem Artichokes

Peel the artichokes, and afterward weigh two pounds of them, and mince them well. (Jerusalem artichokes can be imitated by using half artichoke bottoms, and half sweet potatoes.) Mince up one-quarter of a pound or two medium onions; fry them in butter, and then add the artichokes; fry also. Add two tablespoonfuls of flour, season with salt, sugar, and nutmeg, and moisten with two quarts of white broth. Boil and cook slowly until the artichokes are easily crushed; then drain and mash them; increase the volume of the puree with the broth the artichokes have been cooked in, strain through a sieve or tammy, and heat up without boiling; just when ready to serve thicken the soup with egg-yolks, cream and fresh butter (No 175). A garnishing is made of artichoke bottoms, cut into one-quarter of inch squares.