How to Make It
In a large heavy casserole, combine chicken stock with the onion, garlic, cilantro and cumin. Crumble in the saffron threads and bring to a boil. Reduce the heat to low, season the stock with salt and pepper and simmer for 10 minutes. Add the chicken thighs, legs and wings and simmer for 15 minutes; do not let the stock boil. Add the chicken breasts and simmer until all of the meat is cooked through, 10 to 12 minutes longer.
Remove the chicken from the casserole and let cool. Discard the cilantro. Skin the chicken and, if desired, pull the meat off the bones. Skim the fat from the soup.
Twenty minutes before serving, bring the soup to a simmer. Add the potatoes, yuca, carrots and plantain and simmer over moderate heat for 12 minutes. Add the corn and chicken and simmer until all the vegetables are tender, about 8 minutes longer. Season generously with salt and pepper. Ladle the stew into large bowls, garnish with the avocado and serve.