There’s nothing more comforting than a steaming bowl of Vegetarian Udon Noodle Soup! Made with vegan dashi broth and topped with minced mushroom, tofu, crispy fried eggplant, and bok choy, this is going to be your favorite thing to eat all year round.

A white bowl containing Vegetarian Udon Noodle Soup topped with bok choy, fried tofu, minced mushroom, and crispy eggplant.

One of my recent challenges has been to make more vegetarian and vegan recipes that are approved by my family. They are a tough crowd when it comes to judging my cooking but this Vegetarian Udon absolutely won their hearts. It’s light and delicate, yet so flavorful and comforting; we never get tired of it.

The best part? You can easily customize it with what you have on hand. I’ll show you how I’ve been making this noodle soup!

A white bowl containing Vegetarian Udon Noodle Soup topped with bok choy, fried tofu, minced mushroom, and crispy eggplant.

Why You’ll Love This Vegetarian Udon Noodle Soup

  • The best dashi broth that is vegan and vegetarian friendly.
  • Light, yet so flavorful – It’s the power of umami-rich ingredients, guys!
  • 3 easy cooking steps – Make the soup broth, prepare the toppings, and heat the udon noodles right before assembling.
  • Versatile – You can add any toppings you like to keep the dish interesting!
  • Make-ahead – You can make the soup broth ahead of time and use it within 3-4 days.
  • My non-vegan family approved – By that, it means that the udon soup is so flavorful and satisfying that they didn’t even mind that it didn’t have any meat or fish in the broth or topping.
A black bowl containing Vegetarian Udon Noodle Soup topped with bok choy, fried tofu, minced mushroom, and crispy eggplant.

3 Ingredients That Make Vegetarian Udon Incredibly Delicious!

1. Vegan Dashi (Japanese Soup Stock)

I hope all my vegan and vegetarian readers would try making udon noodle soup with dashi, instead of vegetable broth. Many people don’t realize that dashi can be vegan/vegetarian as dashi is sometimes translated as “seafood stock”.

As I mentioned in this ultimate dashi guide post, you can create an authentic Japanese flavor by using dashi made only with kombu and dried shiitake mushrooms. Using the right soup stock, it will give you a subtle yet umami character in all your Japanese cooking.

2. Sweet and Savory Minced Mushrooms

First I rehydrated the dried shiitake mushrooms to extract their umami and use the liquid for the broth. Instead of tossing the mushrooms away, I minced them up and used them as a topping for the udon soup.

They are practical and economical, so no mushrooms are gone to waste! If you prefer to use the mushrooms for something else, save them for a stir fry, hot pot, or as an addition to rice.

3. Crispy Tofu & Fried Seasoned Eggplant

When I think of a good satisfying ingredient for my omnivore family, I need savory and hearty food for maximum enjoyment.

I love using both fried tofu and eggplants for this dish because frying adds to the overall flavor of the dish. Some of you may want to keep it “healthier” with non-oil and that’s okay. But if you’re all for some good bites, definitely try this. Think this way: Between fried tofu and regular tofu, which one is more flavorful?

I used ready-fried tofu in this recipe and I only needed to fry the eggplants. Eggplant is like a sponge – it absorbs all the flavors from the seasoning! Make sure to coat the eggplant with potato starch (or cornstarch) to give the extra crispiness. Really important!

A white bowl containing Vegetarian Udon Noodle Soup topped with bok choy, fried tofu, minced mushroom, and crispy eggplant.

Stock Up On These Convenient and Delicious Udon Noodles

I recently discovered Annie Chun’s Organic Udon Noodles and was impressed by the quality and convenience of the product. I’ve been eating frozen or refrigerated udon noodles all this time, but I didn’t realize that there are udon noodles like these that are fully cooked and sealed for freshness. You can easily store them in a cool dark place or kitchen pantry and use it whenever you need them! How cool is that?

Annie Chun’s Organic Udon Noodles are:

  • organic, and high in quality.
  • able to be stored in the pantry (yes, at room temperature).
  • pre-cooked, so you can put together a tasty meal in a flash!

It’s great for an emergency and you can keep your refrigerator or freezer space open for other foods.

A black bowl containing Vegetarian Udon Noodle Soup topped with bok choy, fried tofu, minced mushroom, and crispy eggplant.

10 Helpful Cooking Tips

  1. If you have time, soak kombu and dried shiitake mushrooms in water overnight in the fridge for slow steeping; otherwise, just 30 minutes will do.
  2. Cut the eggplants into wedges with skin-on, so eggplant pieces will keep their shape after cooking.
  3. Potato starch (cornstarch) is to make the eggplant crispy. Don’t skip it.
  4. Don’t skimp on the oil when cooking the eggplants. The oil helps to crisp up the texture.
  5. Cut mushrooms into small bits that mimic the meat’s texture.
  6. Keep adding water when simmering the minced mushrooms with seasonings. It will only intensify the flavors as it cooks and you don’t have to worry too much about overcooking it.
  7. Remove kombu from the dashi broth right before boiling it to avoid sliminess and bitterness. You can reuse this kombu to make a furikake rice seasoning or simmered kombu tsukudani (simmered kombu).
  8. Heat up fried tofu in the broth if you like, but it’s not necessary.
  9. Blanch the leafy green vegetable in the same pot of boiling water that you will cook the udon noodles in.
  10. You can add udon noodles directly to the soup broth if you are using Annie Chun’s organic noodles (as its package instructions mention). However, I like to keep my broth clean and clear (no starch from the noodles), so I very quickly loosen them in a pot of boiling water (that I used for blanching veggies).
A white bowl containing Vegetarian Udon Noodle Soup topped with bok choy, fried tofu, minced mushroom, and crispy eggplant.

Substitutions

  • Kombu and Dried Shiitake Mushrooms – They are the key ingredients for the broth. You can use one of them but I strongly recommend both as each ingredient yields different umami flavors. If you really have no access to both ingredients, vegetable broth is your last resort. But it will, unfortunately, lack authentic Japanese flavors.
  • Fresh shiitake mushrooms – I use them to add more volume to the minced dried shiitake mushrooms. You can use any mushrooms such as portobello, king oyster, etc.
  • Eggplant – You can use zucchini, potatoes, sweet potatoes, roasted squash, etc.
  • Fried tofu – You can use crispy baked tofu or regular tofu (Don’t use silken tofu as they break easily).
  • Bok choy – Any green vegetable would work to add freshness. I like some leafy ones that I can blanch right before cooking udon noodles.

Have more questions on ingredients? Leave a comment below and we’ll help you!

More Delicious Udon Recipes You’ll Love:

A white bowl containing Vegetarian Udon Noodle Soup topped with bok choy, fried tofu, minced mushroom, and crispy eggplant.

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A white bowl containing Vegetarian Udon Noodle Soup topped with bok choy, fried tofu, minced mushroom, and crispy eggplant.

Vegetarian Udon

4.72 from 28 votes
There‘s nothing more nourishing and comforting than a steaming bowl of Vegetarian Udon Noodle Soup! Made with vegan dashi broth and topped with minced mushroom, tofu, crispy fried eggplant, and bok choy, this is going to be your favorite thing to eat all year round.  
Prep Time: 15 minutes
Cook Time: 30 minutes
Cold Brew Dashi Steeping Time: 30 minutes
Total Time: 1 hour 15 minutes
Servings: 2

Ingredients
 
 

For Udon Soup Broth

For the Crispy Seasoned Eggplant

For the Sweet and Savory Minced Mushrooms

  • 2 shiitake mushrooms (fresh; substitute portobello, king oyster, etc.)
  • 1 Tbsp soy sauce
  • ½ Tbsp sugar
  • 2 Tbsp water (you can add more to cook for a longer time)

For the Toppings

Japanese Ingredient Substitution: If you want substitutes for Japanese condiments and ingredients, click here.

Instructions
 

  • Gather all the ingredients.
    Vegetarian Udon Ingredients

To Make Vegan Dashi Broth

  • In a medium pot or bowl, add 2½ cups water, 1 piece kombu, and 2 pieces dried shiitake mushrooms. Steep for at least 30 minutes or overnight.
    Vegetarian Udon 1

To Make the Crispy Seasoned Eggplant

  • Trim off the ends of 1 Japanese or Chinese eggplant and cut into roughly 2-inch wedges with the skin-on. The skin will hold the shape together. Without the skin, the flesh will become too soft.
    Vegetarian Udon 2
  • As soon as you cut the eggplant, soak them in water to remove astringency. Set aside for 10–15 minutes and dry them with a paper towel.
    Vegetarian Udon 3
  • Sprinkle 1 Tbsp potato starch or cornstarch and coat the eggplant nicely.
    Vegetarian Udon 4
  • Heat the oil in a large frying pan over medium-high heat (or medium heat on a professional stove). Start frying the eggplant. Do not touch too often. Only flip them when the bottom sides are nicely brown. If they stick to the pan, be patient and wait till the eggplant slice release itself from the bottom when they form a nice crust (but be sure that pan is greased).
    Vegetarian Udon 5
  • If you feel that 3 Tbsp oil is not enough, then add more. Make sure to adjust the heat so it doesn’t take a long time to brown the eggplant. You don’t want overcooked and mushy eggplant.
    Vegetarian Udon 6
  • When the eggplant is golden brown, reduce the heat to medium and season the eggplant with 1 Tbsp mirin and 1 Tbsp soy sauce.
    Vegetarian Udon 7
  • The potato starch (or cornstarch) will thicken the sauce quickly, so flip around to coat the eggplant with the sauce. Then transfer to a plate.
    Vegetarian Udon 8

To Prepare the Other Toppings

  • Cut the 3 oz deep-fried firm tofu cutlet (atsuage) into thin slices.
    Vegetarian Udon 9
  • Cut 2 Shanghai bok choy in half lengthwise.
    Vegetarian Udon 10

To Make the Sweet and Savory Minced Mushrooms

  • Remove the stems of 2 shiitake mushrooms and slice the caps thinly.
    Vegetarian Udon 11
  • Then mince the slices.
    Vegetarian Udon 12
  • Squeeze the liquid out from the dried shiitake mushrooms (keep that liquid for the soup broth) and remove the stems.
    Vegetarian Udon 13
  • Cut the mushroom caps into thin slices and then mince them.
    Vegetarian Udon 14
  • Cut the dried shiitake mushrooms into the same size as fresh shiitake mushrooms.
    Vegetarian Udon 15
  • In a small saucepan, add both mushrooms, ½ Tbsp sugar, and 1 Tbsp soy sauce.
    Vegetarian Udon 16
  • Add 2 Tbsp water and bring it to a simmer. Continue adding water so the bottom of the pot has some liquid.
    Vegetarian Udon 17
  • Simmer until the shiitake mushrooms are tender and absorb the flavors.
    Vegetarian Udon 18

To Make the Udon Soup Broth

  • Transfer the kombu and shiitake dashi broth (including the hydrated kombu) to the saucepan and bring it to a simmer.
    Vegetarian Udon 19
  • Right before boiling, remove the kombu. With a fine-mesh simmer, skim off the foam and scum floating on the surface of the broth.
    Vegetarian Udon 20
  • Add 1 Tbsp mirin, 1 tsp sugar, and 1 Tbsp soy sauce.
    Vegetarian Udon 21
  • Add ¼ tsp Diamond Crystal kosher salt and the fried tofu. Turn off the heat and cover (so it won’t evaporate).
    Vegetarian Udon 22

To Blanch the Bok Choy, Cook the Noodles, and Assemble

  • In a large pot of boiling water, blanch the bok choy just until it turns bright green and tender, about 2 to 2½ minutes, and transfer to a plate. I undercook slightly and so the remaining heat will continue to cook a bit more. For this recipe, I didn‘t “blanch and shock“ for retaining the vegetable color and crunch as I usually do since I wanted to keep the bok choy warm.
    Vegetarian Udon 23
  • Cook or reheat 12 oz udon noodles according to the package instructions.
    Vegetarian Udon 24
  • Drain the udon noodles well and serve them in individual bowls. Divide and serve the fried firm tofu and soup broth.
    Vegetarian Udon 25
  • Top the noodles with blanched bok choy, minced mushrooms, and fried eggplant. Serve immediately with shichimi togarashi (Japanese seven spice) on the side for a spicy kick.
    Vegetarian Udon 26

Notes

Recipe by Namiko Chen of Just One Cookbook. All images and content on this site are copyright protected. Please do not use my images without my permission. If you’d like to share this recipe on your site, please re-write the recipe and link to this post as the original source. Thank you.

Nutrition

Calories: 590 kcal · Carbohydrates: 66 g · Protein: 16 g · Fat: 21 g · Saturated Fat: 2 g · Polyunsaturated Fat: 2 g · Monounsaturated Fat: 2 g · Trans Fat: 1 g · Sodium: 1225 mg · Potassium: 408 mg · Fiber: 8 g · Sugar: 10 g · Vitamin A: 640 IU · Vitamin C: 8 mg · Calcium: 187 mg · Iron: 2 mg
Author: Namiko Hirasawa Chen
Course: Main Course
Cuisine: Japanese
Keyword: eggplant, mushroom, udon noodle, vegan
©JustOneCookbook.com Content and photographs are copyright protected. Sharing of this recipe is both encouraged and appreciated. Copying and/or pasting full recipes to any website or social media is strictly prohibited. Please view my photo use policy here.
Did you make this recipe?If you made this recipe, snap a pic and hashtag it #justonecookbook! We love to see your creations on Instagram @justonecookbook!
4.72 from 28 votes (17 ratings without comment)
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This recipe was so delicious!! My husband and 2 year old son loved it as well. I only had silken tofu and didn’t have the eggplant and it was still incredibly good. Next time I will add the eggplant if I can find the Japanese or Chinese kind. As someone who is half Japanese (and lost my Japanese mother in my 20s), I have appreciated your recipes so much. Thank you for all the effort you put into this site!5 stars

Hi Catharine! Thank you so much for trying Nami’s recipe and for your kind feedback.😊
We’re sorry to hear about your mother, but if you have any recipe questions, please leave a comment. We will be there to help you. 💞
We hope you enjoy many of the recipes on our website. Happy cooking!

Hi Nami,
I just made this for the first time – the kitchen looks like a battlefield now but I have a smile on my face – this was really really good! Thanks for this recipe (and also for many many others…) – quite a few have become regular staples in our family. Wife and kids always happily bounce up and down when they hear that I have been to Düsseldorf (nearby town with a substantial japanese community and the corresponding stores) and brought the necessary ingredients for one of your recipes. I particularly like this one as it provides a savory vegan option. Kids prefer Tonkatsu Donburi, though… 😉 – I have to cook it (the baked version) every other week.
Cheers from Germany,
Martin5 stars

Hi Martin! Aww. Thank you very much for trying Nami’s recipes and for sharing your cooking experience from Germany!
Nami and JOC team read your comment, and we are so happy to hear your family enjoys many recipes from our site.
Thank you very much for your support!💕

Naomi, thank you so much for sharing more vegetarian recipes. Made this last night and it was wonderful!! The dashi had lovely depth and was delicious. I cannot eat gluten or anything corn, so substituted rice noodles for the udon, used a gluten free flour to coat the eggplant before frying, and chickpea flour to coat the tofu before frying. All came out perfectly. My husband had lived in Japan for many years and he loved it!5 stars

Hi Elaine! Nami and a team are very happy to hear you and your husband enjoyed the Vegetarian Udon! Thank you very much for trying this recipe and sharing your cooking experience with us. We have many vegetarian adaptable recipes on site, and we hope you enjoy them! https://www.justonecookbook.com/tags/vegan-adaptable/

THIS WAS SO GOOD!! Amazing simple broth and perfect for colder weather. I made way too many veggies to everything else ratio, but that’s never a bad thing.5 stars

Hi Richard, We are glad to hear you enjoyed this Udon! Thank you very much for trying this recipe and for your kind feedback!

This recipe was amazing! I didn’t have fresh shiitake but it still came out delicious.

I want to thank you Nami for this amazing website. I am currently working my way through the Kansha cookbook, but I found it a bit overwhelming as a newcomer to Japanese cuisine. Thank you for the easy to follow along recipes for us English speakers. I look forward to trying many of your recipes in the near future.5 stars

Hi Ezra,
Thank you very much for trying this recipe and for your kind feedback!
We are glad to hear you enjoy Nami’s Vegetarian Udon.
Happy cooking!🙂

I loved this recipe, thank you so much Nami for doing more vegan recipes! The crispy fried eggplant was perfect – i think I will use it as a side dish for other future meals too.5 stars

Hi Cinnamon!
We are so happy to hear you enjoyed vegan recipes from our website!
Thank you very much for trying many of Nami’s recipes and for your kind feedback.😊

Thank you so much for yet another amazing vegetarian recipe, Nami! I just cooked this tonight and loved it! Perfect for the cold weather, so comforting.4 stars

Hi Teresa!
Thank you very much for trying this recipe and for your kind feedback!
We are glad to hear you enjoyed this vegetarian recipe.

By being a vegetarian/vegan and loving the Japanese way of cooking I will treasure this recipe. Many Thanks.

Hi Adriano!
Aww. Thank you very much!
We are so glad to hear you enjoy the Japanese way of cooking. ☺️

Thanks Nami Your emailed recipes are so often perfect timing I’ve been indulging a craving in Nissin ramen lately I normally only slurp the broth with the noodles and don’t finish it Too much sodium! My broth isn’t up to the challenge but yours will be wonderful! I’ve got the shiitakes but not likely to find Kombu in our local shops But also happy to find a recipe for eggplant too!
いただきます!

Hi, Vanda 蘭!
Thank you very much for subscribing to Nami’s newsletter and for your kind feedback!
We hope you have a chance to try Kombu one day. Thank you for trying Nami’s recipes!