Cream of Peas a la St. Germain

Throw into boiling, salted water, two pounds of medium-sized peas, and boil them for ten minutes with a little piece of mint; drain them, then put four ounces of butter into a saucepan, and when warm, throw in the peas, and let them fry for a few minutes; moisten with white broth, adding a few lettuce leaves, about four ounces, and two ounces of onions; the lettuce to be cut up fine, and the onions minced; season with salt, sugar, and nutmeg, and boil until the peas are thoroughly cooked, then drain, suppress the mint, and mash them in a mortar, moistening them with two and a half quarts of white broth. Press through a sieve or tammy, and return them to the saucepan with a pint of veloute (No. 415); should the puree be too thick, then add more broth; warm it well without boiling, and thicken the soup with egg-yolks, cream and butter, (No. 175). Pour the soup into a soup tureen with some chopped up chervil, and a garnishing of extra fine peas.