Japchae (잡채) is a Korean dish made with sweet potato starch noodles called dangmyeon (당면). The traditional dish includes thin strips of beef and various vegetables, but there are many variations! Depending on the main ingredient accompanying the noodles, the variations are called buchu (garlic chives) japchae, beoseot (mushroom) japchae, gochu (chili peppers) japchae, ueong (burdock root) japchae, kongnamul (soybean sprouts) japchae, etc.
All you need for kongnamul japchae is soybean sprouts and sweet potato starch noodles, along with a few basic seasoning ingredients. Everything else is optional! I added scallions and a little bit of red bell pepper slices for color. The ratio between the soybean sprouts and the noodles can be flexible.