Trim excess fat from chicken thighs, cut into bite-sized pieces, and season with salt and pepper.

Soak dangmyeon in water for 10 minutes until softened, then drain.

Slice onion into 1cm widths, chop chives into 4cm lengths, and cut potatoes into half-moon slices. Soak potatoes in water and drain.

Heat sesame oil in a pan over medium heat, add chicken, and cook until browned. Add onion and potatoes, stirring until coated with oil. Add water and bring to a boil.

Skim off foam, add sauce ingredients, cover, and simmer on low heat for 10 minutes. Add dangmyeon and cook for 3 minutes, then add chives and cook until softened.