Boil the glass noodles in boiling water for 5 minutes, then rinse in cold water.
Slice onion, carrot, green onion, and mushrooms into thin strips.
Heat cooking oil in a pan and stir-fry the vegetables.
Add ground beef and stir-fry it.
Add the boiled glass noodles, season with soy sauce, minced garlic, and pepper.
Place the japchae on top of steamed rice.