Cut the potato into bite-sized pieces and soak in water for 5 minutes. Mince the onion.

Place the potato in a microwave-safe bowl, cover loosely with plastic wrap, and microwave at 600W for 5 minutes.

Heat butter in a frying pan over medium heat, add ground meat, and cook until the meat changes color.

Add minced onion to the pan and sauté until softened. Season with salt and pepper.

Mash the cooked potato, mix in azuki beans, the meat mixture, and soy sauce. Divide into 8 portions.

Shape each portion into a round patty.

Coat each patty with flour, dip in beaten egg, and cover with breadcrumbs.

Heat salad oil to 170°C in a pot, fry the patties until golden brown, flipping occasionally.