Soak fish in water for several hours. Then bring 4 cups fresh water to a boil and drop the fish in pieces. Reduce heat and let simmer.
Meanwhile, combine half the onions with the okra and process or pound into a paste. Add them to the fish.
In separate pot, heat oil to a moderate temperature. Put in remaining onions and saute until golden brown. Chop the tomatoes and stir them in. Cover with the boiling water, about 1 cup, and add pepper. Reduce heat and simmer.
Cover both pots and let them cook for 45 minutes or so, stirring occasionaly. Then uncover the fish and okra mixture and let both pots continue to simmer for another 30-40minutes, stirring as necessary to prevent sticking. to serve, combine the two mixtures and ladle over stiff porridge.
(picure : google image)