Mash the beans with a fork (if you have a blender, you can pulse them a few times until mashed)
Add the egg, salt, pepper and cumin to the beans and mix well.
Add the breadcrumbs to the bean mixture until the mixture is nice and stiff. If the mixture is still soft, add more breadcrumbs until the mixture is stiff enough to hold a shape.
Using about ¼ cup of the bean mixture, shape them into balls and then flatten them to resemble patties.
Heat a frying pan over a medium heat and add some oil. Add your patties to the pan (do not over crowd the pan) and fry them for about 5-10 minutes and then flip over and fry the other side for another 5-10 minutes. They are ready when they get a golden colour and look cooked.
Serve with buns and any toppings you want