Glass noodles of sweet potato starch, tossed with beef, mushrooms and vegetables — each cooked separately — in soy, sugar and sesame oil.
What makes it japchae
Dangmyeon, sweet potato starch noodles — chewy and springy.
Each vegetable cooked on its own, then tossed together.
Soy, sugar and plenty of toasted sesame oil, with sesame seeds.
Where it comes from
Japchae means 'mixed vegetables', and that's what it was at first: a court dish of the seventeenth century, said to have pleased King Gwanghaegun, made with no noodles at all. Dangmyeon — chewy glass noodles — came into it in the twentieth century and became its heart.
It's a dish for occasions — birthdays, holidays, Chuseok — and a fixture on a table of banchan.