Drain and rinse the black beans. In a food processor or mini-chopper (or using a potato masher), pulse them until they are crushed (but not completely puréed). Tip into a large bowl.
Finely chop the spring onions and coriander and add to the beans.
Add the breadcrumbs, lime zest and juice, soy sauce and tahini and mix well until it comes together into a soft burger mix.
Take a heaped tablespoon of mixture, roll it into a ball and flatten into a burger-shaped patty. Continue with the remaining mixture, and chill your mii burgers until required - ideally at least half an hour.
To cook, heat the oil in a large frying pan. Cook the mini burgers over a medium heat for 3-4 minutes on each side until golden brown and crispy.
To serve:
Top the burgers with vegan cheese whilst still in the pan, until it melts.
Split open the buns, spread them with ketchup on both sides, then add the burgers, thin slices of red onion and a cocktail gherkin or two. Serve immediately.
Video
Notes
If your mixture is a little dry and crumbly, add 1 tablespoon water to bring it together, making it easier to shape. If it is a little too sticky, add a few more breadcrumbs.Make these mini burgers whatever size you need to fit the buns you will be using. Mine were 1 heaped tablespoon of burger mix each to make burgers 3-4cm across.Chill for as long as you can before cooking to make sure they keep their shape.