Heat oil in a large soup pot over medium heat. Add celery, carrots, onion, green capsicum and garlic; saute about 8 minutes.
Stir in tomato paste, and cook 1 minute. Add fish stock, potatoes, tinned tomatoes with juice, Worcestershire sauce, chilli, bay leaf and ground black pepper. Simmer until potatoes are tender, about 30 minutes.
Add fish. Simmer until snapper is easily flaked with fork, about 10 minutes.
I have been a little hesitant to make this type of chowder in the past, thinking it might come out a bit acidic, however this recipe comes out very mild and WONDERFUL! Will definitely make again. Thank you! - 15 Feb 2011