Drain and rinse the two tins of beans, place half of each in a bowl and mash until relatively smooth. Add the remaining beans and gently crush them; this adds a little texture to the burgers. Heat a frying pan with a bit of oil over a medium to low heat setting, finely dice half of the onion and place it and the garlic in the pan. Cook until soft and slightly caramelised. Add the onion, breadcrumbs and curry powder to the bean mix, season with salt and pepper to taste.
Form the mixture into patties, I find this mixture is enough to make six, and I use three and freeze three for a later date. Coat the burgers in some flour and sesame seeds; this gives the burgers an amazingly light but crispy outer. Fry gently for a couple of minutes on each side until slightly browned and heated through. Chop the remaining onion into half rings and fry off.
Now for the fun part! We like to use homemade burger buns, but Brioche buns are equally good and toast them gently on the inside in the frying pan after cooking the burgers and onions. Build your burger by popping a patty on the bottom bun, top with onions and the sauce of your choice. It tends to be tomato sauce in here, but a little spoon of mango chutney is terrific too. Then add any extras you fancy; pickles, cheese, whatever you like.
Serve with a lovely salad, maybe some chips, and enjoy!