Cream of Asparagus a la St. Vallier

Mince up fine, five medium-sized onions, throw them into boiling salted water, and let them boil for five minutes, then drain, and fry them in a quarter of a pound of butter without coloring; add four heaping tablespoonfuls of flour, and let fry slowly for several minutes, then put in with them two pounds of green and tender asparagus, cut in one-inch length pieces, washed several times, and blanched for ten minutes in boiling, salted water. Moisten with two quarts of broth, and when the asparagus is done, drain it off, and mash it in a mortar diluting it with its own broth; pass all through a fine sieve, and put the puree into a saucepan, to heat; season with salt, sugar and nutmeg, and after it begins to boil, remove all the fat arising to the surface; just when ready to serve, thicken the soup with raw egg-yolks, diluted in cream, and incorporate therein some fine butter. Serve in a soup tureen with a garnishing of green peas and small quenelles, three-sixteenths of an inch in diameter, laid through a cornet on a buttered pan, and poached in some boiling salted water, poured into the pan; when done, drain them, and add them to the soup.