- For Japchae (Korean noodles with vegetables), prepare the medium rice noodles according to the package instructions. Drain them and use kitchen scissors to cut them into smaller pieces.
- In a bowl, mix all the sauce ingredients thoroughly.
- In a pan, heat 1 tbsp sesame oil and sauté the onion for a few minutes until it becomes translucent. Add the peppers and carrot and continue sautéing for a few more minutes until the vegetables soften slightly. They should remain crisp rather than fully soft. Remove the vegetables with a slotted spoon, then add the meat and mushrooms. Sauté for 5–6 minutes until the meat is nicely browned and cooked through.
- In a small saucepan, pour in the sauce and simmer over medium-high heat for a few minutes until it is reduced by about half. Avoid boiling the sauce over very high heat, as it will evaporate too quickly.
- Add the vegetables and beef to the sauce and stir to combine. Then add the medium rice noodles, remove from the heat, drizzle with a little sesame oil, season with pepper, and serve.
