Cook the potatoes

• Place the potatoes in a saucepan of cold salted water.
• Bring to a boil and cook until fork tender.
• Drain the potatoes.

Make the pork and onion filling

• Dice the onion and cook it in a pan with a little oil until translucent.
• Add the ground pork and cook until nearly done.
• Add the soy sauce and mirin and finish cooking.

Mash and combine

• Mash the potatoes, leaving some rough chunks.
• Add the pork and onion mixture, salt and pepper and mix to combine.

Shape around the cheese

• Form the potato mixture into palm-sized rounds.
• Press a cheese cube into each round and wrap the potato tightly around it.

Bread the croquettes

• Coat each croquette in flour.
• Dip in the beaten egg.
• Roll in the panko breadcrumbs.

Fry until golden

• Fry the croquettes for a couple of minutes on each side until golden brown.
• Let them drain on a wire rack.

Serve

• Serve hot with tonkatsu sauce for dipping.