Vegan Japchae with Shiitake Mushrooms and Spinach
Chewy sweet potato noodles tossed with savory-sweet soy and toasted sesame oil, silky spinach, and deeply browned shiitake and vegetables. Each ingredient is cooked separately so colors stay bright and textures stay distinct. It's served warm or at room temperature.
- Prep
- 25 min
- Cook
- 25 min
- Wait
- 5 min
- Total
- 55 min
- Makes
- About 6 cups (4 main-course servings or 6 side servings)
Steps
Before you start
- Buy Korean sweet potato noodles (dangmyeon) made from sweet potato starch. Glass noodles made from mung bean or rice are different and cook faster.
- Cut all vegetables before you turn on the stove. The stir-frying goes quickly and the vegetables are cooked in batches.
- Set out a large mixing bowl for collecting the cooked vegetables and a colander in the sink for the noodles and spinach.
- Check that your soy sauce and sugar are vegan. Some refined white sugar is processed with bone char, so use organic or labeled-vegan sugar if that matters to you.
Mix the sauce
- In a small bowl, stir together the soy sauce, sugar, 2 tbsp (30 ml) of the sesame oil, grated garlic, water, and black pepper.
- Stir for about 1 minute until the sugar dissolves and no grains remain at the bottom.
- Set aside.
- Bring a large pot with about 3 quarts (3 L) of water to a boil over high heat while you prep the vegetables.
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Ready when: Sugar is fully dissolved and the sauce looks smooth and dark brown.
Tip: Keep the sauce within reach. You'll use it in three stages.
Prep the vegetables
- Slice the shiitake, carrot, onion, bell pepper, and scallions as described in the ingredient list.
- Keep the cut ingredients in separate piles, because each is cooked on its own.
- Trim the spinach and rinse it well in cold water.
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Ready when: Carrot and pepper strips are similar in thickness so they cook at the same speed.
Tip: Cutting vegetables to similar sizes keeps the finished dish easy to eat and look neat.
Blanch the spinach
- Add the spinach to the boiling water and push it under with tongs.
- Cook for 30 seconds, until bright green and wilted.
- Lift it out with tongs, keeping the water boiling, and plunge it into a bowl of ice water or cold running water for 1 minute.
- Squeeze it firmly in your hands to remove as much water as you can, then chop it roughly into 3-inch (7 cm) lengths.
- Toss with 1 tbsp of the sauce and set aside.
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Ready when: Spinach is bright green, limp, and feels damp but not dripping after squeezing.
Tip: Squeezing well matters. Wet spinach will dilute the sauce and make the noodles soggy.
Boil the noodles
- Add the dry noodles to the same boiling water and cook, stirring occasionally, for 6–7 minutes.
- Taste one: it should be tender but still very chewy, with no hard white center.
- Drain in a colander and rinse under cold water for 15 seconds to stop the cooking.
- Drain well.
- Cut the noodles 3–4 times with kitchen scissors into manageable lengths of about 8 inches (20 cm).
- Toss in the large mixing bowl with the remaining 1 tbsp (15 ml) sesame oil and 2 tbsp of the sauce.
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Ready when: Noodles are translucent, tender, and chewy all the way through.
Tip: Sweet potato noodles are slippery and long. Cutting them before they dry makes the dish much easier to toss and eat.
Cook onion and carrot
- Heat 1 tbsp of the neutral oil in the large skillet over medium-high heat until it shimmers, about 1 minute.
- Add the onion, carrot, and a pinch of the salt (about ⅛ tsp).
- Stir-fry for 3 minutes, until the onion turns translucent and the carrot is bright and just tender with a slight crunch.
- Scrape into the bowl with the noodles.
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Ready when: Onion is translucent at the edges and carrot is bright orange and slightly softened but still crisp.
Tip: Don't crowd the pan. Work in batches so the vegetables stir-fry instead of steaming.
Brown the mushrooms
- Return the skillet to medium-high heat and add 1 tbsp of oil.
- Add the shiitake in an even layer and leave undisturbed for 1 minute to brown, then stir-fry for 3 more minutes with a pinch of salt (about ⅛ tsp).
- Add into the bowl.
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Ready when: Mushrooms are golden brown at the edges, shrunken, and smell nutty.
Tip: Resist the urge to stir constantly. Letting the mushrooms sit gives them better browning.
Cook pepper and scallions
- Add the last 1 tbsp of oil to the skillet over medium-high heat.
- Add the bell pepper and stir-fry for 1½ minutes, then add the scallions and a final pinch of salt (about ⅛ tsp) and cook for 30 seconds more.
- Transfer to the bowl.
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Ready when: Pepper strips are glossy and crisp-tender; scallions are bright green and just wilted.
Toss everything together
- Add the spinach to the bowl with the noodles and cooked vegetables.
- Pour over all the remaining sauce (about 4 tbsp).
- Toss with tongs or clean hands for 1–2 minutes, lifting from the bottom, until every strand is evenly coated and dark brown.
- For more heat and a slightly better flavor, return everything to the skillet over medium-low heat and stir for 2 minutes.
- Taste and add the last ⅛ tsp salt if needed.
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Ready when: Noodles are evenly glossy and dark, with no pooled sauce in the bottom of the bowl.
Tip: Add the sauce a little at a time and taste. The noodles will keep absorbing it as they sit.
Garnish and serve
- Sprinkle with the toasted sesame seeds and serve right away while warm, or let it rest for 5 minutes to reach pleasant room temperature, which is a traditional way to eat japchae.
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Ready when: Seeds are evenly scattered and noodles look glossy.
Tip: Rub the sesame seeds between your fingers as you sprinkle them to release more aroma.
Good to know
Tips
- Cook each vegetable separately. Doing so keeps their colors vivid and their textures distinct, which is the key to good japchae.
- Don't over-rinse the noodles with hot water, or leave them undrained. Excess water dilutes the sauce.
- Taste the noodles near the end of cooking time since brands vary. Pull them when chewy but not hard in the center.
- For extra protein, add pan-fried firm tofu cubes or sliced baked tofu in the final toss.
Make ahead
"Cook the vegetables, spinach, and noodles up to 1 day ahead, keeping each in a separate covered container in the fridge. Toss with the sauce and warm in a skillet just before serving. The sauce can be made 3 days ahead and kept in the fridge."
Storage & reheating
"Room temperature: up to 2 hours. Refrigerator: airtight container up to 4 days. Freezing is not recommended because the noodles turn mushy. Reheat in a nonstick skillet over medium heat with 1–2 tbsp of water for 3–4 minutes, stirring, until hot. A microwave also works at 1 minute intervals."
Substitutions
- fresh shiitake mushrooms → cremini or oyster mushrooms. The flavor will be milder. Cook for the same time until golden brown.
- soy sauce → tamari. This makes the dish gluten-free. Sweet potato noodles are naturally gluten-free.
- granulated sugar → maple syrup (2 tbsp / 30 ml). Gives a slightly deeper sweetness and is naturally vegan. Skip the dissolving step.
- red bell pepper → zucchini half-moons or sliced cabbage. Cook for the same 1½ minutes until crisp-tender.
