Instructions: Make the broth: Hold the ginger with a pair of tongs directly over an open flame, or place it directly on a medium-hot electric burner. While turning, char until the edges are slightly blackened and ginger is fragrant, 3 to 4 minutes. Char the onions in the same manner. Peel and discard the blackened skins of the ginger and onions, then rinse. Set aside.

Lightly toast star anise and cloves in a dry pan for 2 minutes. Place the star anise, cloves and peppercorns in a cheesecloth square. Tie with a piece of kitchen twine; set aside.

In a large stockpot, bring 5 quarts water to a rolling boil. Add the chicken backs and chicken halves. Boil vigorously for 3 minutes, then reduce the heat to a simmer. Skim the surface as necessary to remove any fat or foam. Add the charred ginger, onions, fish sauce, sugar, and salt. Cook until the chicken is just done, about 30 minutes. Remove the halved chicken (but not the chicken backs), and set aside to cool.

Add the spice bag to the pot, and cook the broth for a total of 1 1/2 hours. Remove and discard the spice bag. Reduce the heat to very low.

Remove the skin from the chicken, and discard. Hand-shred half of it into bite-sized strips. (Save the other half for another use, such as chicken salad. A whole chicken is required to make a deep, rich broth.)

To serve, bring a large pot of water to a boil. Add noodles, and cook until white and softened, but still resilient, 3 to 5 minutes. Drain, rinse immediately in cold water, and drain again completely before serving.

Reheat the noodles in a microwave or dip briefly in boiling water, and place in warm bowls. Garnish each bowl with a few slices of yellow onion and some shredded chicken. Ladle over a generous amount of boiling broth. Top with scallions and cilantro. Invite guests to garnish and season their bowls with bean sprouts, fresh herbs, chiles, lime juice, and black pepper.

This recipe yields 6 servings.

If you would like to email yourself the recipe for later use, or share the recipe with your friends or family, enter the email addresses below and this recipe will be emailed to you and others as well.