In a large sufuria add your cooking oil and let it get hot. Add your onions. Cook until translucent.

Add the boiled potatoes and bananas. cook for 3 mins. season to your liking

Mash your pre-boiled black beans till they are well mashed.

Add your potatoes and bananas to your mushed black beans and continue mashing. If its too hard you can add a little bit of warm water till you get a fine mixture. Serve with your desired accompaniment.