1. Discard chili stems and seeds (and trim out veins if less heat is desired). Finely mince chilies.
2. With a potato masher or fork, mash avocados until almost smooth, leaving a few tiny chunks. Add chilies and salt to taste.
3. In a 3- to 4-quart pan, bring broth to a boil over high heat.
4. Meanwhile, mound equal portions of the mashed avocado mixture in shallow soup bowls.
5. Ladle the hot chicken broth around avocado in the soup bowls. Sprinkle each serving with the chopped cilantro.