Japchae (Korean Sweet Potato Noodle Stir-Fry)

updated Jul 17, 2023
Japchae, or Korean sweet potato noodle stir-fried with carrots, spinach, and mushrooms, and garnished with green onions and sesame seeds, on a plate with chopsticks
Credit: Photo: Murray Hall; Food Stylist: Jessie YuChen

Sweet potato glass noodles get stir-fried in a sweet-savory sauce with baby spinach and thinly sliced carrots, onions, mushrooms.

Serves4 to 6

Prep20 minutes to 25 minutes

Cook20 minutes to 25 minutes

Jump to Recipe
We independently select these products—if you buy from one of our links, we may earn a commission. All prices were accurate at the time of publishing.
Japche plated.
Credit: Photo: Murray Hall; Food Stylist: Jessie YuChen

If you were to ask me what one of my favorite Korean dishes is, I would immediately say japchae, a popular dish in Korean cuisine. This noodle stir-fry has a wonderful sweet-savory element from soy sauce and sugar; toastiness from sesame oil; and lots of texture from the chewy, bouncy noodles, colorful veggies, and beef. It’s the perfect harmony of flavors.

Japchae is mostly about prep: You need to marinate the beef; cut up the onions, carrots, and mushrooms; and cook the sweet potato noodles. But once the prep is done, the cook time is pretty quick and similar to other noodle stir-fries.

Start with cooking the beef (you can also skip the beef to keep things vegetarian), then stir-fry the veggies before tossing in the noodles and sauce. The key to delicious japchae is the last step: One last drizzle of toasted sesame oil to add a punch of flavor that stays in the foreground.

What Kind of Noodles Do You Use to Make Japchae?

Dried Korean sweet potato noodles, sometimes labeled as sweet potato vermicelli or called glass noodles, are needed to make japchae. They usually come packed in bundles in large packages, so I try to look for packages where the bundles are 8 ounces each, which is the amount needed for this recipe. When purchasing the noodles, double-check that they’re not Korean cold noodles made from buckwheat.

The noodles will have a gray tint to them, then cook up to be more clear after they’re boiled, which is where they get the nickname glass noodles. For japchae, I like to rinse the noodles in cold water after they’re cooked, then drizzle on some sesame oil for flavor and to keep the noodles from sticking together.

Credit: Photo: Murray Hall; Food Stylist: Jessie YuChen

Do You Eat Japchae Cold or Hot?

The beauty of japchae is that you can eat it hot, room temperature, or even cold. It makes a great on-the-go lunch, as the noodles don’t get soggy and there’s a nice balance of vegetables and starch. This dish is also nice for potlucks, as it doesn’t have to be served hot.

What to Eat with Japchae

Japchae is usually eaten as part of a multi-course meal, most often with little plates of Korean side dishes like kimchi known as banchan. Japchae is lovely with the following:

Japchae Recipe

Sweet potato glass noodles get stir-fried in a sweet-savory sauce with baby spinach and thinly sliced carrots, onions, mushrooms.

Prep time 20 minutes to 25 minutes

Cook time 20 minutes to 25 minutes

Serves 4 to 6

Nutritional Info

Ingredients

For the beef (optional):

  • 1 tablespoon

    plus 2 teaspoons soy sauce

  • 1 1/2 teaspoons

    mirin

  • 1 1/2 teaspoons

    toasted sesame oil

  • 1 1/2 teaspoons

    packed dark brown sugar

  • 1

    (8 to 10-ounce) boneless New York or ribeye steak

  • 1 tablespoon

    vegetable or canola oil

For the japchae:

  • 1

    medium carrot

  • 1/2

    medium yellow onion

  • 4 ounces

    fresh shiitake mushrooms (about 8 medium or 5 large)

  • 2 cloves

    garlic

  • 1 (5-ounce) package

    baby spinach (about 5 packed cups)

  • 1

    medium scallion (optional)

  • 8 ounces

    dried Korean sweet potato noodles or sweet potato vermicelli

  • 3 tablespoons

    soy sauce or tamari

  • 2 tablespoons

    packed dark brown sugar

  • 1 teaspoon

    kosher salt, divided, plus more as needed

  • 2 tablespoons

    toasted sesame oil, divided

  • 1 tablespoon

    vegetable or canola oil

  • 1/4 teaspoon

    freshly ground black pepper, plus more as needed

  • 1 tablespoon

    toasted white sesame seeds, plus more for garnish

Instructions

Show Images

Marinate the beef (optional):

  1. Place 1 tablespoon plus 2 teaspoons soy sauce, 1 1/2 teaspoons mirin, 1 1/2 teaspoons sesame oil, and 1 1/2 teaspoons packed dark brown sugar in a medium bowl and stir to combine.

  2. Trim the excess fat from 1 (8 to-10 ounce) boneless New York or ribeye steak. Cut in half horizontally (also known as butterflying), then very thinly slice across the grain. Add to the soy sauce mixture and toss to combine. Let sit at room temperature while you prepare the noodles and vegetables.

Make the japchae:

  1. Bring a large saucepan of heavily salted water to a boil over high heat. Meanwhile, prepare the vegetables.

  2. Prepare the following, placing each in a separate pile on a rimmed baking sheet or large plate: Peel 1 medium carrot and cut crosswise into thirds. Cut each piece lengthwise into 1/4-inch thick planks. Stack the planks and cut lengthwise into 1/4-inch wide matchsticks (about 1 cup). Thinly slice 1/2 medium yellow onion (about 1 cup). Trim the stems from 4 ounces fresh shiitake mushrooms and thinly slice the caps (about 2 cups). Finely chop 2 garlic cloves and pile on top of the mushrooms.

  3. Measure out 5 ounces baby spinach if needed (about 5 packed cups). Thinly slice 1 medium scallion if using.

  4. Add 8 ounces dried Korean sweet potato noodles to the boiling water and stir to separate them. Boil until cooked through, about 5 minutes. Meanwhile, place 3 tablespoons soy sauce, 2 tablespoons packed dark brown sugar, and 1/2 teaspoon of the kosher salt in a small bowl and stir until the sugar and salt are dissolved.

  5. Drain the noodles in a colander and rinse with cold water until cool. Leave in the colander and cut with kitchen shears into 6 to 8-inch lengths. Drizzle with 1 tablespoon of the sesame oil and toss to coat.

  6. If using beef, heat 1 tablespoon vegetable oil in a large frying pan (preferably nonstick) over medium heat until shimmering. Add the beef and spread into an even layer. Let cook undisturbed for 1 minute. Stir-fry until just cooked through, 30 seconds to 1 minute more. Using tongs, transfer to the colander with the noodles.

  7. Heat 1 tablespoon vegetable oil in the same pan (no need to clean) over medium heat until shimmering. (If not using beef, heat 1 tablespoon vegetable oil in a large frying pan.) Add the carrot, onion, remaining 1/2 teaspoon kosher salt, and 1/4 teaspoon black pepper. Cook, stirring occasionally, until the onion is softened and starting to brown, 6 to 8 minutes.

  8. Add the mushrooms and garlic and cook, stirring occasionally and scraping up the browned bits from the bottom of the pan with a wooden spoon, until the mushrooms are tender, 3 to 4 minutes.

  9. Add the spinach and cook until mostly wilted, about 2 minutes. Add the reserved noodles, beef, and soy sauce mixture. Toss until heated through and the noodles are evenly coated in sauce, 2 to 3 minutes.

  10. Remove the pan from the heat. Drizzle with the remaining 1 tablespoon sesame oil, sprinkle with 1 tablespoon toasted white sesame seeds, and toss to combine. Taste and season with more kosher salt and black pepper as needed. Garnish with the scallions and more sesame seeds. Serve warm or at room temperature.

Recipe Notes

Korean sweet potato noodles: These noodles are also known as starch noodles or Korean vermicelli, and are made from sweet potato starch and water. Do not confuse them with Korean “cold noodles,” which are made from buckwheat.

Dried shiitake mushrooms: Substitute 1 ounce dried whole shiitake mushrooms for the fresh. Soak in hot tap water and let sit until softened, at least 4 hours or up to overnight. Trim off the tough stems and thinly slice the caps. They need more cooking time than fresh shiitakes, so cook with the onions and carrots. Add the garlic with the spinach.

Storage: Leftovers can be refrigerated in an airtight container for up to 4 days.