Vegan Udon Noodle Soup with Spring Vegetables

This vegan udon noodle soup is light and delicious with a simple Japanese-style broth and crisp spring vegetables. The broth is the perfect balance of sweet and savoury with a hint of lemon to compliment the freshness of the broccolini, asparagus and snow peas. The flat udon noodles are deliciously chewy and perfect for slurping up all that delicious broth!

This vegan udon noodle soup is light and delicious with a simple Japanese-style broth and crisp spring vegetables.

I’m on a total spring vegetable kick right now. Can you blame me? I’ve gotta take advantage of all that lovely (and cheap) asparagus, broccolini and snow peas while I can get them! I’ve used this combination, along with radishes for colour (and also in season) in a myriad of recipes from pasta to risotto to this vegan galette. Now comes soup!

This spring vegetable udon noodle soup is super easy to make as these particular vegetables are the tastiest served crisp-tender. That means that you can throw them into the pot of boiling noodles just before the noodles are done to just give them a quick blanch. Then simply arrange everything in your bowl and pour over the hot broth to warm.

A delicious and light vegan udon noodle soup in a tasty Japanese-style broth and fresh spring vegetables.

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Making the vegan udon noodle soup base isn’t tricky but you’ll need to plan ahead if you want to make your own vegetarian dashi. It is possible to buy packaged vegetarian dashi powders, which would save you quite a bit of time and make this a 15-minute recipe, but I think you would compromise on taste if you went that route.

To make homemade vegetarian dashi, you need just two ingredients: kombu (kelp / dried seaweed) and dried shiitake mushrooms. Simply leave a small piece of kombu and a couple of dried shiitake mushrooms in 4 cups (1 litre) of water to steep overnight. That’s it, strain it and it’s ready for your soup.

There’s also a quick method for making vegetarian dashi that Lukas Volger describes in his wonderful cookbook Bowl. That is to bring the water to a bare simmer, remove the pot from the heat, add the kombu and mushrooms and let sit for 30 minutes. I usually do the overnight method but the quick method will work if you don’t plan ahead.

Vegan udon noodle soup with spring vegetables is easy to make and showcases the best of the season's produce.

To finish up the udon noodle soup base just add soy sauce, mirin and sake. Yes, these are specialty ingredients (well, not the soy sauce) but if you like Japanese flavours, I’d recommend picking up a couple of small bottles to make this vegan udon noodle soup and the toshikoshi soba recipe I also have on the blog. They’re also great to add to tofu or mushroom marinades and stir fries.

Esta sopa de udon vegana es ligera y deliciosa con un caldo simple al estilo japonés y crujientes verduras frescas de primavera.

Vegan Udon Noodle Soup with Spring Vegetables

Yield: 4
Prep Time: 5 minutes
Cook Time: 10 minutes
Total Time: 15 minutes

Vegan udon noodle soup with fresh, crisp spring vegetables in a light and lemony Japanese-style broth.


For the udon noodle soup base

  • 4 cups (1 litre) water
  • A 5 gram (0.2 oz) piece of kombu (about 10 cm² / 4 in²)
  • 2 dried shiitake mushrooms
  • 2 tablespoons mirin
  • 2 tablespoons soy sauce
  • 1 tablespoon sake
  • 1 teaspoon sea salt (or to taste)

For the vegan udon noodle soup

  • 3 bundles of dried flat udon noodles
  • 40 snow peas, halved
  • 12 broccolini
  • 20 asparagus spears, tough ends snapped off (mine were thin, if you’ve got thick ones you may need less than 20)
  • A small bunch of enoki mushrooms (100 grams / 3.5 oz)
  • 4 radishes, thinly sliced
  • 1 green onion, thinly sliced
  • The zest of one lemon
  • Sesame seeds to garnish (optional)


For the udon soup base

  1. The night before, place the water, kombu and shiiake mushrooms in a bowl and put in the refrigerator to steep. Alternatively, bring the water to a light simmer, remove from the heat, add the kombu and shiitake mushrooms and steep for 30 minutes.
  2. Remove the kombu and mushrooms and transfer the broth to a pot. Bring to a simmer and add the mirin, soy sauce, sake and salt to taste.

For the vegan udon noodle soup

  1. Bring a large pot of water to the boil and add the noodles. Cook for as long as indicated on the package directions. Two minutes before the noodles are ready, add the broccolini, asparagus and snow peas to the pot. Drain the pot into a colander and rinse with lukewarm water, gently rubbing the noodles together to remove the excess starch.
  2. Arrange the noodles, broccolini, asparagus, snow peas and enoki mushrooms in four bowls and ladle over the hot broth. Top with the radishes, green onion, lemon zest and sesame seeds. Serve immediately.


Note: prep time does not include steeping the kombu for the dashi, which could take from 30 minutes to overnight.

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Nutrition Information:
Yield: 4 Serving Size: 1
Amount Per Serving: Calories: 907Total Fat: 9gSaturated Fat: 2gTrans Fat: 0gUnsaturated Fat: 6gCholesterol: 0mgSodium: 1164mgCarbohydrates: 153gFiber: 60gSugar: 73gProtein: 65g

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