For the stock: Place the chicken in a pot and add the garlic, bay leaves, carrots, parsley, rosemary, thyme, peppercorns, lemon and onion. Cover with 12 cups water and bring to a boil. Reduce the heat and simmer at a low rolling boil for 40 minutes. Remove the chicken and let cool. Strain the stock, then return it to the pot and simmer until reduced to about 8 cups. Discard the skin and bones of the chicken and shred or dice the meat.
For the soup: Heat the EVOO in a soup pot over medium-high heat. Add the carrots and cook for a few minutes, then add the leeks and cook until softened, a few more minutes. Add the escarole and cook until wilted. Season with salt, pepper and a little nutmeg. Add the chicken and stock, and heat through.
Bring a large pot of water to a boil for the pasta, and season with salt. Add the pasta and cook until al dente.
Divide the pasta among 4 bowls, nesting a bundle of noodles in each dish. Ladle the soup over the pasta and serve.
Cook's Note: The soup (without the pasta) can be made ahead of time, cooled and then stored in the refrigerator.