How to Make It
In a large pot, combine the chicken, beef and turkey. Fill the pot with 4 1/2 quarts of water and bring to a boil. Cover partially and simmer over moderate heat, skimming off the fat and foam that rise to the surface, until the broth looks clear, about 30 minutes. Add the onion, celery, carrots, tomatoes, peppercorns and parsley sprigs. Simmer until the broth is very flavorful and reduced to 5 cups, about 2 1/2 hours. Strain the broth through a sieve; discard the solids.
In a large saucepan, bring the strained broth to a boil. Add the amaranth, cover and cook over moderately low heat until the amaranth is tender, about 30 minutes. Stir in the spinach.
In a small bowl, beat the eggs with the cheese, chopped parsley, nutmeg and 1/2 teaspoon each of salt and pepper. Remove the saucepan from the heat and drizzle in the eggs. Cover the soup and let stand, without stirring, for 8 minutes. Gently stir the eggs to break them into strands. Season the soup with salt and pepper and serve garnished with cheese.
For a less expensive version, use 5 pounds of chicken backs and 1 pound of beef shin.