In a medium kettle, boil both white and sweet potatoes, about 15 minutes.
In a large kettle, gently saute chopped onions,red and green peppers and tomatoes in oil.
Next add fish cut into small pieces to the kettle and saute.
Add partly cooked white and sweet potatoes, along with enough cooking water to simmer the soup.
Simmer until potatoes and fish are done.
Add chopped parsley and chopped scallions to the kettle.