For fufu with palm sauce, first prepare fufu. To do this, peel the plantains, cut them into pieces and cook for fifteen minutes. Then mash them.
Alternatively, mix puree and flour with cold water, season with salt. Heat slowly. Add boiling water over medium heat, stirring throughout, until the mixture takes on a soft but chewy consistency.
Let cool briefly and form into dumplings in a wet baking dish with your hands.
For the palm sauce with fish, in a large saucepan, melt palm oil paste with water and boil down for about 10 minutes. Season with salt and pepper and bring to a boil briefly.
Add remaining ingredients and simmer over medium heat for about an hour until sauce thickens.
Serve fufu with palm sauce while still warm.