- 1 (3-lb) whole chicken
- 12 cups cold water
- 1 (6-oz) slice boneless ham (1/3 inch thick) such as Smithfield ham or baked Virginia ham
- 1 bunch scallions
- 1 (1-inch) piece fresh ginger, cut into 1/4-inch slices
- 4 garlic cloves, crushed
- 1/2 cup coarsely chopped fresh cilantro stems, roots discarded
- 1 1/2 teaspoons salt
- 6 oz dried rice noodles
- 3 cups finely shredded iceberg lettuce (1/4 head)
- Cover chicken with 12 cups water in a 6- to 8-quart pot.
- Cut off one third of ham (trim if necessary) and cut into 1/3-inch dice, then chill. Add remaining two thirds ham to pot.
- Trim scallions, then cut 1 scallion into thin slices and reserve. Cut remaining scallions crosswise into thirds and add to pot along with ginger, garlic, and cilantro stems.
- Cook chicken, uncovered, at a bare simmer 3 hours (do not let boil), skimming foam as necessary. (Do not stir, or stock will be cloudy.)
- Transfer chicken with tongs to a cutting board, reserving stock. When chicken is cool enough to handle, remove breast meat and shred into 3-inch-long strips, discarding skin. Chill strips and reserve remaining chicken for another use. Pour stock through a fine-mesh sieve into a large bowl, discarding solids and skimming off fat (see cooks' note, below).
- Bring 6 cups stock with salt to a simmer.
- While stock is coming to a simmer, bring about 2 quarts water to a boil in a 4-quart saucepan. Soak noodles in a bowl of very hot water until softened, about 10 minutes, then drain in a colander. Add noodles to boiling water and cook 1 minute, then add lettuce and cook 30 seconds. Drain in a colander.
- Using tongs, divide noodles and lettuce among 6 deep bowls, forming small nests, then top with shredded chicken and diced ham. Ladle 1 cup hot broth into each bowl and sprinkle with sliced scallion.