Cut the new potato into thin strips and soak in water for 5 minutes. Drain the water.

Boil water in a pot and cook the potato strips for 1-2 minutes. Drain them in a colander.

Make a slit in the mentaiko roe and extract the contents.

In a bowl, mix mentaiko, mayonnaise, powdered cheese, and black pepper. Add the potatoes and mix well.