Cut napa cabbage into 2cm strips, trim enoki mushrooms and cut in half, slice the white part of the leek into 4cm pieces, and peel and thinly slice the ginger.

Heat sesame oil in a pan over medium heat and sear the chicken drumsticks skin-side down until golden brown, about 5–6 minutes.

Transfer the seared chicken drumsticks to a pot, add enough water to cover, bring to a boil, and simmer for 3 minutes. Drain the water, rinse the pot, and return the chicken along with the green part of the leek, ginger, and soup base ingredients. Bring to a boil, then reduce to low heat and simmer covered for 20 minutes.