Place the whole chicken in a large stockpot and cover generously with water. Add salt and bring to the boil, skim any foam from the surface of the soup. Reduce to a low simmer and add the onion skin on, garlic, celery and 1 peeled carrot cook for 90 minutes with the lid ajar.
Remove the chicken and put to the side to cool slightly. Strain the soup and return to the stove. In the meantime add remaining carrots, corn, potatoes & zuchinni. Shred the meat off the chicken and add back to the soup. Cook the soup for a further 10 minutes. Salt to taste.
Serve the soup up into bowls and top with fresh avocado, onion, coriander, chili (optional) and a good squeeze of lime juice. Dunk your tortilla as you slurp up the taste of Mexico.