In a large pot, bring 4 cups of water to a boil.
Once the water is boiling, reduce the heat to low.
Gradually add the cassava flour (or yam flour) to the water, stirring continuously with a wooden spoon to prevent lumps from forming.
Continue to stir the mixture vigorously until it thickens and becomes smooth and stretchy. This process will take about 10-15 minutes. The fufu should pull away from the sides of the pot and form a cohesive dough.
Once the fufu is cooked and smooth, remove it from the heat.
Wet your hands with water to prevent sticking, then shape the fufu into small balls or patties.
Enjoy your meal!