Take the kidney beans in a bowl and mash well. Add onion, soya granules, paprika, onion powder, garlic powder, mixed herbs, chilli flakes, salt and potato.
Finely chop 3-4 parsley sprigs and add. Mix well.
Divide the mixture into equal portions and shape them into patties and coat them with breadcrumbs.
Preheat oven to180º C.
To make cabbage salad, halve and slice purple cabbage and put it in another bowl. Add yogurt, smoked paprika and salt and mix well.
Roughly chop remaining parsley sprigs and to the cabbage-yogurt mixture. Mix well.
Place the burger buns on a baking tray and brush some olive oil on them. Place the tray in the preheated oven and toast for 2-3 minutes.
Heat some olive oil in a non-stick pan. Place the patties in it and sear, turning sides, till golden brown on both the sides. Set aside.
Slice the toasted burger buns horizontally into halves. Spread some tomato ketchup on the inner sides of the bun halves.
Place lettuce on the base buns, top with a patty and some cabbage salad.