Dice the potatoes into small cubes.

Soak the diced potatoes in cold water for 10 minutes, then rinse.

Mix sugar, oligosaccharide, and plum extract in equal amounts (1 tbsp each).

Let the potatoes sit in the mixture for 10 minutes.

Transfer the potatoes to a pot and cook without adding extra water.

Cover the pot and simmer for 5 minutes.

Uncover and gently stir while cooking until potatoes are 80% cooked.

Add soy sauce and continue simmering until fully cooked.

Shake the pot gently instead of stirring to prevent breaking the potatoes.

Add chopped green onion and simmer until fully reduced.