Slowly sweat off the onion, garlic and green peppers in the olive oil for about 10 minutes. After sweating, cover to stew very gently for about 15 minutes, stirring occasionally. This breaks down the green pepper to a more palatable form.
Add the parsley, saffron, bay leaves, peppercorns, tomatoes, cassava, tomato paste, wine and water. Cover and simmer for ten minutes.
Add the squid and clams or cockles and simmer for another ten minutes.
Add the fish, prawns and mussels in layers. Don't stir too much as you'll want the fish to cook in the broth.
Sprinkle with a heavy dose of the black pepper, cover and cook for about ten minutes or until the fish is cooked through and the mussels and clams or cockles are open. Discard any that don't open.
Ladle the stew gently into vat-sized bowls and sprinkle with the chopped coriander.
Serve with bread or rice.