Peel the potatoes, dice them into cubes, and soak them in cold water to remove excess starch.

Mix 1 cup of water with soy sauce, sugar, mirin, black pepper, minced garlic, and minced green onion to prepare the seasoning sauce.

Heat 2–3 tbsp of oil in a pan and add the soaked potatoes. Stir-fry them over medium heat.

Cook the potatoes until they turn golden brown on the surface.

Increase the heat to high and pour the prepared seasoning sauce over the potatoes. Cook until the sauce starts to thicken.

Add the chopped green onion and reduce the heat to medium. Continue cooking until the potatoes are tender.

If the potatoes are not fully cooked, add a bit more water and continue simmering until tender.

Once the sauce is fully reduced, drizzle 1/2 tbsp sesame oil and sprinkle sesame seeds. Turn off the heat.