Pulse mushrooms and one of the red onions in a food processor.
Brown the chopped mushrooms and onions in a large pan with 3-4 tbsp olive oil and a pinch of salt, for 10-12 minutes on high heat. Then, set aside to cooldown.
Chop the other red onion and garlic in the processor without making a puree, add red beans, breadcrumbs, and pulse again.
Add boiled corn, mustard, cumin, meatball mix, salt and black pepper and give it a last mix.
Add egg, parsley and cooled red onion-mushroom mixture in and knead.
Wet your hands and shape the mixture into balls or long finger shaped meatballs.
Shallow fry in sunflower oil or any cooking oil.
