Japchae Sweet Potato Glass Noodles

If using beef, marinate it with 1 tablespoon soy sauce, 1/2 tablespoon sesame oil, 1 teaspoon sugar, and a pinch of black pepper for at least 10 minutes. Blanch spinach quickly in boiling water, then rinse with cold water, squeeze out excess liquid, and season with 1 teaspoon soy sauce and 1/2 teaspoon sesame oil. Prepare all other vegetables by slicing them thinly or julienning.

Boil a large pot of water and cook the sweet potato glass noodles according to package directions, usually 6-8 minutes, until transparent and chewy. Drain well and rinse briefly with cold water to prevent sticking. In a large bowl, toss the cooked noodles with 2 tablespoons soy sauce, 1 tablespoon sesame oil, and 1 tablespoon sugar. Cut the noodles into shorter lengths if desired with kitchen shears.

Heat 1 tablespoon vegetable oil in a large wok or pan over medium-high heat. Stir-fry the sliced onions until softened, about 2 minutes, then remove and set aside. Repeat with carrots, cooking for 2-3 minutes until slightly tender-crisp. Next, stir-fry bell peppers for 1-2 minutes. Finally, cook the mushrooms until they release their moisture and brown slightly, about 3-4 minutes. Cook the minced garlic with the mushrooms for the last minute.

If using, add the marinated beef to the hot pan and stir-fry until fully cooked through and no longer pink, about 3-4 minutes. Break up any clumps of meat as it cooks. Remove from the pan and set aside with the other cooked ingredients.

In a small bowl, whisk together the remaining 3 tablespoons soy sauce, 2 tablespoons sugar, 2 tablespoons sesame oil, and 1/2 teaspoon black pepper. This will be the main dressing for the noodles and vegetables.

In the large bowl with the seasoned noodles, add all the cooked vegetables, the blanched spinach, and the cooked beef (if using). Pour the prepared Japchae sauce over the ingredients. Using your hands, gently but thoroughly mix everything together until the noodles and vegetables are evenly coated with the sauce. Ensure the noodles are not tangled.

Transfer the Japchae to a serving platter or individual bowls. Garnish generously with toasted sesame seeds. Serve warm or at room temperature. Japchae is delicious as a main dish or a vibrant side dish.