Peel and chop the potatoes into bite-sized pieces. Soak them in water to remove excess starch, then drain. Microwave the potatoes in a heatproof container covered with plastic wrap for 5–6 minutes at 600W until soft. Mash the potatoes while hot.

Place the canned corn in a plastic bag, add half of the potato starch (1/2 tbsp), and coat evenly. Cut the roasted seaweed into 10 pieces using kitchen scissors.

Drain the saba can and flake the fish. Add the flaked saba, mashed potatoes, chopped green onion, and salt to the plastic bag with the corn. Mix thoroughly and divide into 10 portions. Shape each portion into a ball, coat with the remaining potato starch (1/2 tbsp), and wrap with a piece of seaweed.