Japchae (Korean Sweet Potato Noodle Stir-Fry)

Name: Japchae (Korean Sweet Potato Noodle Stir-Fry)
Prep time: 28 min
Cook time: 23 min
Total time: 51 min
Yield: 6 servings
Cuisine: Korean
Ingredients: 8 oz (225 g) dried sweet potato starch noodles (dangmyeon), left dry and uncut; 6 oz (170 g) beef sirloin or ribeye, trimmed, sliced against the grain into thin strips about 2 inches (5 cm) long and ⅛ inch (3 mm) thick; 1 tbsp (15 ml) soy sauce; 1 tsp (4 g) granulated sugar; 1 tsp (5 ml) toasted sesame oil; 1 clove (3 g) garlic, finely minced; 5 oz (140 g) fresh spinach, washed, thick stems trimmed; ½ tsp (2½ ml) toasted sesame oil; 1 medium (about 4 oz) (110 g) medium carrot, peeled and cut into thin matchsticks about 2 inches (5 cm) long; 1 medium (about 5 oz) (140 g) yellow onion, halved and sliced into thin ¼-inch (6 mm) half-moons; 4 oz (115 g) fresh shiitake mushrooms, stems removed, caps thinly sliced; 4 scallions (60 g) scallions, cut into 2-inch (5 cm) lengths, thick pieces halved lengthwise; 3 tbsp (45 ml) neutral oil such as canola or avocado oil, divided into 3 equal portions of 1 tbsp; ¾ tsp (4 g) kosher salt, divided: ¼ tsp for spinach, and 3 pinches for the vegetables; 3 tbsp (45 ml) soy sauce; 2 tbsp (25 g) granulated sugar; 2 tbsp (30 ml) toasted sesame oil; 2 cloves (6 g) garlic, finely minced; 2 tbsp (30 ml) water; freshly ground black pepper, to taste, about ¼ tsp; 1 tbsp (9 g) toasted sesame seeds, for finishing

From the MyKitchenBank Kitchen

Chewy, glossy sweet potato starch noodles tossed with tender beef, spinach, carrots, onion and mushrooms in a savory-sweet soy and toasted sesame sauce. Each component is cooked separately so every vegetable keeps its color and texture. It's good warm or at room temperature.

Prep: 28 min
Cook: 23 min
Wait: 17 min
Total: 1 hr 8 min
Makes: About 8 cups (6 side-dish or 4 main-course servings)

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Ingredients

6 servings

For the noodles
8 oz (225 g) dried sweet potato starch noodles (dangmyeon), left dry and uncut
For the beef
6 oz (170 g) beef sirloin or ribeye, trimmed, sliced against the grain into thin strips about 2 inches (5 cm) long and ⅛ inch (3 mm) thick
1 tbsp (15 ml) soy sauce
1 tsp (4 g) granulated sugar
1 tsp (5 ml) toasted sesame oil
1 clove (3 g) garlic, finely minced
For the vegetables
5 oz (140 g) fresh spinach, washed, thick stems trimmed
½ tsp (2.5 ml) toasted sesame oil
1 medium (about 4 oz) (110 g) medium carrot, peeled and cut into thin matchsticks about 2 inches (5 cm) long
1 medium (about 5 oz) (140 g) yellow onion, halved and sliced into thin ¼-inch (6 mm) half-moons
4 oz (115 g) fresh shiitake mushrooms, stems removed, caps thinly sliced
4 scallions (60 g) scallions, cut into 2-inch (5 cm) lengths, thick pieces halved lengthwise
3 tbsp (45 ml) neutral oil such as canola or avocado oil, divided into 3 equal portions of 1 tbsp
¾ tsp (4 g) kosher salt, divided: ¼ tsp for spinach, and 3 pinches for the vegetables
For the sauce
3 tbsp (45 ml) soy sauce
2 tbsp (25 g) granulated sugar
2 tbsp (30 ml) toasted sesame oil
2 cloves (6 g) garlic, finely minced
2 tbsp (30 ml) water
freshly ground black pepper, to taste, about ¼ tsp
1 tbsp (9 g) toasted sesame seeds, for finishing

Equipment (7)

Large pot (5–6 quart / 5–6 L) for boiling noodles and blanching spinach
12-inch (30 cm) nonstick skillet or wok
Large mixing bowl (4–5 quart / 4–5 L)
Kitchen scissors for cutting noodles
Colander
Sharp knife and cutting board
Instant-read thermometer

Steps

Before you start

Use dried Korean sweet potato starch noodles (dangmyeon). Other noodles won't give the same chewy, slippery texture.
Slice the beef while it is partly frozen (about 20 minutes in the freezer) so you can cut it paper-thin.
Cut all vegetables into similar thin strips before you turn on the stove. The cooking goes quickly.
Set up a large mixing bowl to collect the cooked components, and a bowl of ice water for the spinach.

1
Marinate the beef
- In a small bowl, combine the sliced beef with 1 tbsp soy sauce, 1 tsp sugar, 1 tsp toasted sesame oil and 1 minced garlic clove.
- Mix with your hands until every strip is coated, then leave it at room temperature while you prep the vegetables.
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Ready when: Beef strips look evenly coated and slightly glossy
Tip: Don't marinate longer than 30 minutes. The soy sauce will start to cure the thin slices and make them salty.
2
Prep the vegetables
- Cut the carrot into thin 2-inch (5 cm) matchsticks.
- Slice the onion into ¼-inch (6 mm) half-moons.
- Slice the shiitake caps thinly.
- Cut the scallions into 2-inch (5 cm) lengths and halve any thick pieces lengthwise.
- Keep each vegetable in its own pile on the cutting board or in separate bowls.
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Ready when: All vegetables are cut into similar thin strips
Tip: Uniform strips cook at the same speed and make the finished dish easy to eat with chopsticks.
3
Mix the sauce
- In a small bowl, stir together 3 tbsp soy sauce, 2 tbsp sugar, 2 tbsp toasted sesame oil, 2 minced garlic cloves, 2 tbsp water and the black pepper.
- Stir for about 30 seconds until the sugar has dissolved and no grains remain at the bottom of the bowl.
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Ready when: Sugar is fully dissolved and the sauce looks uniform
4
Blanch the spinach
- Bring a large pot with 3 quarts (3 L) of water to a rolling boil over high heat.
- Prepare a bowl of ice water.
- Add the spinach and cook for 30 seconds, just until bright green and wilted.
- Lift it out with tongs or a spider into the ice water, leaving the pot of water on the heat for the noodles.
- Once cool, squeeze the spinach firmly with your hands to remove as much water as possible, cut it into 3-inch (7 cm) lengths, and toss with ½ tsp sesame oil and ¼ tsp salt.
- Set it aside in the large mixing bowl.
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Ready when: Spinach is bright green and wilted, and no water drips out when squeezed
Tip: Squeeze hard. Wet spinach will water down the sauce and make the finished noodles soggy.
5
Boil the noodles
- Return the pot of water to a boil if it has stopped.
- Add the dry noodles and boil for 6–7 minutes, stirring occasionally so they don't stick, until translucent, soft and chewy.
- Bite one to check.
- It should be tender with a pleasant chew and no hard white core.
- Drain in a colander, rinse briefly under cold water, and drain well.
- Using kitchen scissors, cut the noodles a few times into roughly 8-inch (20 cm) lengths.
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Ready when: Noodles are translucent, slippery and chewy with no hard center
Tip: Don't overcook. They will absorb sauce and soften further when stir-fried.
6
Cook onion and carrot
- Heat a 12-inch (30 cm) nonstick skillet over medium-high heat for 1 minute.
- Add 1 tbsp neutral oil and the onion with a pinch of salt.
- Stir-fry for 2 minutes until the onion turns translucent.
- Add the carrot with another pinch of salt and cook 2 more minutes until crisp-tender and bright orange.
- Transfer to the large mixing bowl with the spinach.
- Wipe out the skillet if any bits have browned.
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Ready when: Onion is translucent and carrot is bendable but still has some bite
Tip: Don't crowd the pan. The vegetables should sizzle, not steam.
7
Cook mushrooms and scallions
- Return the skillet to medium-high heat.
- Add 1 tbsp neutral oil and the shiitake with a pinch of salt.
- Cook, stirring often, for 3 minutes until the mushrooms release liquid and are lightly browned at the edges.
- Add the scallions and stir for 30 seconds until bright green.
- Transfer to the mixing bowl.
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Ready when: Mushrooms are golden at the edges and the pan is mostly dry
8
Sear the beef
- Return the skillet to high heat.
- Add the last 1 tbsp neutral oil and spread the marinated beef in a single layer.
- Cook, stirring and breaking apart the strips, for 1½–2 minutes until no pink remains and the edges are lightly browned.
- The beef should reach 145°F (63°C).
- Transfer to the mixing bowl with the vegetables.
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Ready when: No pink remains and the beef reads 145°F (63°C)
Tip: Cook the beef in two batches if the strips pile up. Crowding steams the meat instead of searing it.
9
Glaze the noodles
- Reduce the heat to medium-low.
- Add the cut noodles and the sauce to the skillet.
- Toss constantly with tongs for 2–3 minutes until the noodles absorb most of the sauce, turn a glossy dark brown and the liquid in the pan is gone.
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Ready when: Noodles are glossy and evenly brown, and there is no liquid pooling in the pan
Tip: Keep the heat low. High heat can scorch the sugar before the noodles take up the sauce.
10
Toss and serve
- Transfer the glazed noodles to the large bowl with the spinach, vegetables and beef.
- Toss gently with tongs or clean hands for about 1 minute so everything is evenly mixed.
- Taste and add a pinch of salt or a splash of soy sauce if needed.
- Sprinkle with the toasted sesame seeds and serve warm or at room temperature.
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Ready when: Vegetables and beef are evenly distributed through the noodles
Tip: Mixing by hand (with clean or gloved hands) is the traditional method. It distributes the ingredients without breaking the noodles.

Good to know

Tips

Cooking each vegetable separately keeps its color and texture. Don't skip this even though it takes extra time.
Always cut the noodles after boiling. Whole noodles are almost impossible to toss and eat.
Add a bit more sesame oil at the end if the noodles seem dry after resting, since they keep absorbing flavor.
For a colorful version, add thin strips of red bell pepper with the carrot and a fried egg garnish (cooked until the white is set).

Make ahead

"Cook and season all components up to 1 day ahead and refrigerate them separately. Reheat the noodles in a skillet with 1 tbsp water over medium heat, then toss with the other components. Or make the whole dish and serve it at room temperature."

Storage & reheating

"Room temperature: up to 2 hours. Refrigerator: airtight container up to 4 days. Freezer: not recommended because the noodles turn mushy. Reheat in a skillet over medium heat with 1–2 tbsp water, tossing for 2–3 minutes until hot, or microwave covered for 1–2 minutes with a splash of water."

Substitutions

beef sirloin or ribeye → extra-firm tofu (pressed, cut into strips) or extra shiitake mushrooms. For a vegetarian version, marinate and sear the tofu the same way, until golden.
fresh shiitake mushrooms → cremini mushrooms or rehydrated dried shiitake. Squeeze rehydrated mushrooms dry and use 6 medium caps.
fresh spinach → baby bok choy or Swiss chard leaves. Blanch 45–60 seconds for chard, then squeeze dry.
soy sauce → tamari. Use for a gluten-free dish. Check that the noodles are 100% sweet potato starch.