Japanese Vegan Udon Noodle Soup

Prep: 10 mins
Cook: 20 mins
Total: 30 mins
Servings: 3 to 4 servings

A staple of Japanese cuisine, udon noodles have won the hearts and palates of food enthusiasts around the world. Thick, silky, and filling, these wheat noodles are commonly found in soups, with or without animal-based proteins, but always surrounded by thinly sliced vegetables and flavorful ingredients like soy sauce, rice vinegar, and ginger.

This particular vegan version of this Japanese-inspired soup is made with Chinese broccoli, scallions, fresh cilantro, and peanuts. It's similar to a traditional recipe, so you'll find it warming and filling but not heavy.

Dried udon noodles can be found in the international section of most supermarkets, but sometimes Asian markets and supermarkets sell the frozen version. What you really want is the fresh version, which you might be able to acquire from a local Japanese restaurant, as they're difficult to find elsewhere; if you can't find dried or frozen, use soba noodles instead.

Easy to make, our udon soup is a great introduction to classic Japanese flavors and a tempting light lunch or dinner.

Japanese vegan udon noodle soup with Chinese broccoli in a bowl

The Spruce Eats / Madhumita Sathishkumar

"This quick soup pairs a flavorful broth with chewy udon noodles for a satisfying dish. Feel free to play around with the ingredients to get the flavors just how you like them—I liked adding a splash of mirin. Tastes great topped with steamed or fried tofu." —Laurel Randolph

Vegan udon noodle soup tester image
A Note From Our Recipe Tester

Ingredients

For the Broth:

  • 4 cups low-sodium vegetable broth

  • 1 (1-inch) piece ginger, sliced

  • 2 tablespoons soy sauce

  • 1 tablespoon rice vinegar

  • 1 tablespoon vegetarian oyster or mushroom sauce

  • 1/2 teaspoon chili paste

  • 1 pinch granulated sugar

  • Kosher salt, to taste

  • Freshly ground black pepper, to taste

For the Chinese Broccoli:

  • 1 tablespoon peanut oil

  • 1/2 tablespoon minced ginger

  • 2 cloves minced garlic

  • 1 teaspoon sesame oil

  • 1 pound Chinese broccoli, coarsely chopped

For Assembling:

  • 1 pound fresh or frozen udon noodles, cooked according to package directions (or 14 ounces dried)

  • 2 medium green onions, thinly sliced

  • 1/4 cup coarsely chopped cilantro

  • 1/4 cup roasted, salted peanuts

Steps to Make It

Make the Broth

  1. Gather the broth ingredients.

    Ingredients for Japanese broth recipe gathered

    The Spruce / Madhumita Sathishkumar

  2. In a medium saucepan, combine the vegetable broth with the pieces of ginger, soy sauce, rice vinegar, oyster or mushroom sauce, chili paste, and sugar. Stir to combine and bring to a boil. Cover the pot and reduce to a simmer.

    Saucepan with broth covered with a lid

    The Spruce Eats / Madhumita Sathishkumar

  3. Allow broth to simmer for at least 10 minutes. Remove the pieces of ginger from broth and discard. Taste and season lightly with salt and pepper if needed.

    Pieces of ginger being removed from the broth with a spoon

    The Spruce Eats / Madhumita Sathishkumar

Make the Chinese Broccoli

  1. Gather the Chinese broccoli ingredients.

    Ingredients for Chinese broccoli recipe gathered

    The Spruce Eats / Madhumita Sathishkumar

  2. In a separate large skillet, heat the peanut oil and add the minced ginger, garlic, and sesame oil over medium heat. Cook 1 to 2 minutes or until fragrant.

    Oil, garlic, and ginger being added to a frying pan

    The Spruce Eats / Madhumita Sathishkumar

  3. Add the Chinese broccoli. Sauté for a few minutes, or until the broccoli is just tender and a lively green color. Remove from the heat and set aside.

    Chinese broccoli being stirred with a wooden spoon in a frying pan

    The Spruce Eats / Madhumita Sathishkumar

Assemble the Noodle Soup

  1. Gather the ingredients for assembly.

    Ingredients for Japanese udon noodle soup recipe gathered

    The Spruce Eats / Madhumita Sathishkumar

  2. Prepare individual bowls by placing a serving of noodles in each, topping with the prepared Chinese broccoli, a generous amount of warm broth, some sliced green onions, chopped cilantro, and roasted peanuts. Serve.

    Ladleful of stock being added to Japanese udon noodle soup in a bowl

    The Spruce Eats / Madhumita Sathishkumar

Recipe Variations

  • Feel free to add more soy sauce, rice vinegar, oyster sauce, chili paste, and sugar to taste. You want a flavorful broth since it will infuse the other ingredients with its flavor.
  • You can add ingredients like mushrooms (dried or fresh) or mirin for extra flavor.
  • Our quick recipe is vegan and uses vegetable broth as a base, but if you'd like a more classic version, you can replace it with dashi, which has fish ingredients in it.

Kitsune Noodles

Kitsune noodles are a classic preparation of udon noodles. Topped with fried tofu, the soup is really delicious and filling thanks to the added protein in the tofu. For this version, simply follow the recipe as is but top each bowl of soup with a slice of fried tofu.

  • Simply press and remove any excess liquid from a package of extra-firm tofu, slice it into 2 pieces by cutting it diagonally and then slice each triangle in half by its thickness. Pat the tofu triangles dry with paper towels, drench in cornstarch, and deep fry in 350 F oil until golden brown on both sides. Sprinkle with sea salt.
  • Top the soup with a triangle of tofu. For a more elaborate version of this dish, you can fry the tofu twice for an extra special texture.

How to Store and Freeze

  • The best way to store noodles, whether in the refrigerator or in the freezer, is to separate the broth and veggies from the noodles into separate sealed containers; this is often the way you will receive Asian noodle-based soups if you purchase them for takeout. Store in the refrigerator for 3 to 5 days.
  • If you want to freeze the soup, just freeze the broth and veggies. Noodles like udon don't reheat well after they've been frozen. Just reheat in a saucepan over medium-low heat until it's hot all the way through.

Is Udon the Same as Ramen?

Udon and ramen are both noodles used in soup-based Japanese dishes loaded with noodles, veggies, and broths with similar ingredients. However, udon noodles are thicker, whiter, and typically vegan; ramen noodles are thinner, often made with eggs (so they're more yellow in color), and curlier in shape. Both of them, however, contain wheat flour; only soba is usually gluten-free, made from buckwheat (but read the package to be sure if that's a concern).

Nutrition Facts (per serving)
251 Calories
10g Fat
33g Carbs
10g Protein
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Nutrition Facts
Servings: 3 to 4
Amount per serving
Calories 251
% Daily Value*
Total Fat 10g 13%
Saturated Fat 2g 8%
Cholesterol 0mg 0%
Sodium 1358mg 59%
Total Carbohydrate 33g 12%
Dietary Fiber 6g 20%
Total Sugars 5g
Protein 10g
Vitamin C 77mg 385%
Calcium 79mg 6%
Iron 2mg 12%
Potassium 574mg 12%
*The % Daily Value (DV) tells you how much a nutrient in a food serving contributes to a daily diet. 2,000 calories a day is used for general nutrition advice.
(Nutrition information is calculated using an ingredient database and should be considered an estimate.)

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