Peel the bananas and wash them in cold water. Put into a pot, add the water, and cover.
Boil for 10 minutes, then reduce the heat and continue to cook. The mixture will turn yellow when well-cooked.
Drain the water. Mash the bananas with a wooden spoon. Wrap the mashed food in foil and place on a steaming basket.
Place the steamer inside a large pot and add water. Steam on low heat for 20 minutes. Serve while hot.