Peel and finely chop the onion, peel and crush the garlic cloves, finely chop the coriander.
Allow the beans to cool a bit before stirring in the breadcrumbs, soy sauce, egg, coriander and salt and pepper to taste.
Heat a little bit of olive oil in a frying pan over a low heat. Cook the patties for about 5 minutes per side until nicely browned and warmed through. Serve the burgers with the buns and your selection of toppings.