Squeeze out the liquid from grated onions and place in a large bowl.

Add black beans, bell peppers (capsicum), garlic, ground cumin, paprika, cayenne pepper, breadcrumbs, parsley and oregano. Season with salt and pepper. Mix.

Using a fork or potato masher, mash the mixture lightly so you will get a coarse mixture.

Divide the mixture into flour equal portions.

Lightly wet your hands.

Carefully roll the mixture into balls.

Gently squeeze down to flatten into patties, about 3 cm thick. Set aside.

Spread the burger buns with butter.

Place them in a pan over medium heat, buttered side facing down. Toast. Set aside.

Add oil to the same pan. Add black bean patties, in batches, and fry, flipping occasionally, for about 4 minutes on each side or until cooked through. Set aside.

To assemble, spread the burger buns with mayonnaise. Place lettuce on the bottom bun and then layer with black bean burger patties, tomatoes and pickled onions. Place the top bun on the onions.