Step 1

Soak the glass noodles in hot water for 15 minutes, then drain and set aside. Pre-soaking will soften the noodles and make them easier to cook.

Step 2

Slice beef (or pork) into thin match sticks (about 1/4-inch thick) against grain and season with soy sauce, sugar, and sweet rice wine; set aside.

Step 3

In a mixing bowl, combine all the japchae sauce ingredients, and set aside.

Step 4

Heat 1 tablespoon oil in a large skillet or wok over medium high heat. Add onion, carrot, pepper, and a pinch of salt; stir-fry until soft but have a slight crunch to complement the soft noodles. Add sliced shiitake mushrooms and another pinch of salt. Continue to stir-fry until soft. Add more oil if needed.

Step 5

Add spinach at the end and stir-fry until spinach is wilted. Remove the skillet from the heat and transfer the vegetables to a large plate to cool.

Step 6

Reheat the pan over high heat with the remaining 1 tablespoon oil, add the beef (or pork) and stir-fry until fully cooked. You will see the juice coming out from the meat. Transfer the meat to the large plate with the reserved vegetables, reserving the juice in the pan.

Step 7

Add the drained glass noodles to the pan with the meat juices. Pour the japchae sauce over the noodles and toss to combine. Let the noodles cook over medium heat until they are soft and the sauce liquid is mostly absorbed into the noodles, about 3-4 minutes.

Step 8

Reduce the heat to low. Add the vegetables and meat back to the pan over the noodles. Add sesame oil and sesame seeds and toss all together to incorporate. Drizzle more sesame oil if you wish. Taste and season more according to your taste.