Boil the prepared lotus root in boiling water for about 5 minutes.

Rinse the boiled lotus root under cold water to cool it down.

Add the lotus root to a pan with the dark soy sauce, guk-ganjang, sugar, and mirin, pour in enough water to almost cover the lotus root, and simmer over medium heat for about 15 minutes.
Tip.Lotus root takes longer to cook through than you'd expect, so if the liquid reduces too much before it's done, add a little water at a time as you continue cooking.

Once most of the liquid has reduced, add the rice syrup and cook for another 3 minutes to coat the lotus root in a glossy glaze.
Tip.Add the rice syrup at the very end so the dish gets a nice shine without burning.

Finish by sprinkling toasted sesame seeds on top.