In a large bowl, mash about two-thirds of the dried black beans with a fork or potato masher until mostly smooth but still slightly chunky. Leave the remaining beans whole for texture.
Stir in the breadcrumbs until the mixture is firm enough to handle. If the mixture seems too wet, add 1 tablespoon more breadcrumbs.
Divide the mixture into four equal portions. Form each portion into a patty about 3/4 inch thick. Press the edges firmly to help the patties hold together.
Place the formed patties on a plate lined with parchment paper. Chill in the refrigerator for at least 30 minutes before cooking. This helps them set.
Cook the patties in a lightly oiled skillet over medium heat for 5-7 minutes per side, or until heated through and browned. Alternatively, grill over medium heat for 5 minutes per side.
Notes
For the best texture, ensure your black beans are as dry as possible before mashing.
You can substitute rolled oats for breadcrumbs if you prefer a different binder.
These patties freeze well after chilling; wrap individually before placing them in a freezer bag.