- Place sliced potatoes in a pot and fill with water. Bring to the boil, then cook over medium heat for 10 mins, or until tender. Drain, then place in a large mixing bowl. Mash until smooth, then season with salt and pepper. Place in the fridge for at least 1-2 hrs, or until completely cooled.
- Fit a piping bag or zip-lock bag with a round piping tip. Place the mayonnaise into the bag, then place in the fridge until needed.
- Once potatoes have cooled, roll them into bite-sized balls and place on a plate.
- Add the flour, eggs and panko breadcrumbs into 3 separate bowls.
- Dip the potato balls into the flour, followed by the egg, then the panko breadcrumbs. Place onto a plate. Repeat with remaining potato, adding more flour, eggs and panko breadcrumbs if needed.
- Heat oil in a deep fryer or pot to 180°C. In batches of 5-6, cook the korokke for 2 mins, or until golden brown. Drain on paper towel.
- Allow korokke to cool slightly before piping with mayonnaise. Top with tobiko and microherbs, then serve.