Place the chicken, water, onion, peppercorns,salt, coriander seeds, celery and carrot in a saucepan. Bring to the boil, reduce heat and simmer 45 minutes. Remove the chicken and reserve, strain and reserve the stock.
Cut the corn off the cobs. Add to the chicken stock, cover and simmer 10 minutes. Shred the chicken and return to the soup. Stir in the tomato sauce and add salt if needed.