Peel and slice the cassava and plantain with a knife into medium-size pieces, take out the cassava's core and the plantain's tiny seeds, and rinse.
Place the pieces in a saucepan, cover with water, add optional salt, and cook over medium heat.
Boil for 30 minutes or until fork-tender. Drain the water.
Add the cooked plantain and cassava to a food processor and blend. Use a spoon to move it around as necessary to ensure even blending. Add water by the spoonful as needed until you achieve desired texture. It should be soft and stretchy.
Turn it onto a wet plate or bowl and fold it into itself until it is smooth.
Using a mortar and pestle, start by pounding the plantain into a smooth dough and set it aside. Then do the same for the cooked cassava.
Combine the plantain and the cassava.
Mold the mixture into the portion size of your choice and place it in serving bowls.
The fufu is ready to serve with the soup of your choice.
