• Prep Japchae Noodles: In a large sauté pan or frying pan with high sides, bring about 6 cups of water to a boil, and cook the noodles until translucent and soft, about 6 to 8 minutes. Turn off heat. Using tongs, remove noodles to a colander leaving the water in the sauté pan. Rinse noodles under cold running tap water. Tap strainer to full drain noodles. Transfer to a large mixing bowl and mix noodles with 1 teaspoon sesame oil.
• Make Spicy Sauce: Make the Spicy Japchae Sauce while the noodles are cooking. Combine the sauce ingredients—4 tablespoons soy sauce, 4 tablespoons gochugaru, 2 tablespoons gochujang, 1 tablespoon maple syrup, 4-5 minced garlic cloves, and 1 teaspoon sesame oil—in a small bowl.

Cook Japchae Vegetables

• Wipe out sauté pan if necessary. Heat 1 tablespoon cooking oil over medium heat. Add green onions and stir fry until the onions are translucent about 2 minutes. Transfer to the bowl with the noodles.
• Drizzle the pan with another 1 tablespoon cooking oil. Add the shredded cabbage and carrots and stir fry until just cooked through, about 3 minutes. Do not overcook. Cabbage and carrots taste best when slightly crisp. Transfer cooked cabbage and carrots to the bowl with the noodles.
• Drizzle the pan with another 1 tablespoon cooking oil. Add the mushrooms and cook until cooked through, about 3 minutes. Transfer to the bowl with the noodles.
• Pour Spicy Japchae Sauce over noodles and vegetables. Mix to combine. You can use tongs, but hands are actually the best "tool" to really evenly distribute all the vegetables and sauce. Taste and adjust with additional soy sauce if needed.
• Garnish with roasted sesame seeds.