Shiitake Mushroom Udon Noodle Soup is the ultimate Japanese comfort meal on nights that call for instant warmth. This plant-based udon soup has a rich broth with big umami mushroom flavour and plenty of mushrooms, noodles, and all your favourite toppings for the bowl.
Why You’ll Love These Noodles
- FRESH! SHIITAKE! MUSHROOMS! Need I say more? This soup is packed with earthy shiitake mushrooms, which are used in two ways: the stems are simmered in the flavourful broth and the caps are seared to caramelized perfection.
- Got a dietary restriction? No problem. I have instructions to adapt this udon noodle soup for different diets, including gluten-free, low sodium, low fat, and low carb.
- This mouthwatering recipe for vegan mushroom udon soup comes together quickly and with only a handful of ingredients.
History & Origins
Udon noodles have a long history that goes all the way back to the 7th century, when the recipe was first brought from China to Japan. Buddhist monks are credited with bringing udon noodles into the mainstream in the 11th century and since then its popularity has continued to grow to where it is today—that is, an internationally beloved comfort food!
Shiitake mushrooms are another mainstay of Japanese cuisine, where they are a natural source of umami—a fifth taste that combines sweet, sour, salty, and bitter all in one. In this recipe, both the stems and caps of shiitake mushrooms add umami to the soup. This recipe uses fresh mushrooms, but I also use dried ones in my recipes for Kongbiji Jjigae, Vegan Japchae, and Buddha’s Delight.
What You’ll Need
A few important notes on some of the ingredients used in this Shiitake Mushroom Udon Noodle Soup recipe:
Shiitake Mushrooms: Dried and fresh shiitake mushrooms are an essential ingredient in Japanese cuisine. They are packed with tons of umami flavour. Plus they get nice and chewy when cooked and soak up lots of delicious broth.
Dried Kombu: Kombu is a type of dried seaweed used in Japanese cooking which also gives savoury flavour and balance to broths. If you see some white dust on your kombu, don’t worry. It’s a nutrient called mannit that gives kombu its natural umami. Don’t wipe or rinse it off!!
Onion & Garlic: Onions and garlic are simmered with shiitake stems (and then discarded) to make a quick but super-flavourful broth.
Soy Sauce: The ultimate soup seasoner! I like Kikkoman for Japanese recipes. For a gluten-free option, tamari sauce works well.
Scallions: Fresh scallions add brightness to this earthy, comforting recipe.
Inari: A totally optional topping, I love to finish this udon soup with a packet of inari, also known as marinated fried tofu skin.
Udon Noodles: Fresh udon noodles cook in only a few minutes and have a delightfully springy and perfectly chewy texture. (Well, not fresh fresh, I mean the squishy ones that come in the sealed packages that you can store in your pantry.) Frozen udon works too!
For a full list of ingredients and quantities, refer to the recipe card at the bottom of this post.
Ingredient Substitutions
If you’re following a specific diet or need to be aware of allergies, here are a few ways you can modify this recipe:
- Gluten-free: Use a gluten-free udon noodle option (like these brown rice udon noodles) and choose tamari or gluten-free soy sauce over regular.
- Oil-free: Skip the sautéeing and simmer the sliced shiitake mushroom caps directly in the strained broth for 5 minutes or until cooked.
- Low carb: Use shirataki noodles (like these konjac spaghetti noodles, which are nearly zero carb and zero calorie) in place of the udon noodles.
If you made this recipe with a successful substitution, please let me know! Post a comment describing what you did so I can add it to this section and help future readers. (Leave your name blank if you don’t want to be credited.)
Flavour Variations
- Spicy Udon: Give this Japanese udon soup a spicy kick with a spoonful of shichimi togarashi or chili crisp.
- Miso Udon: Replace part of the salt in this recipe with 1 tablespoon miso paste.
- Kitsune Udon: Serve this udon Kitsune-style by topping it with a piece or two of abura-age (a Japanese deep-fried tofu pocket). Kitsune means fox in Japanese. In Japanese mythology, the fox god’s favourite food is fried tofu! Not kidding!
- Shiitake Mushroom Soba: Replace the udon noodles with soba for an equally delicious but slightly lighter take on this shiitake mushroom soup!
Step-by-Step Process
Step 1: Remove and set aside the stems of each mushroom for the shiitake udon soup broth. Thinly slice the mushroom caps.
Step 2: Add the mushroom stems, onion, garlic, and water to a small stockpot. Bring to a simmer, then reduce heat and simmer gently until the onion loses its raw smell.
Step 3: Meanwhile, heat the oil in a skillet over high heat. Sauté the mushrooms until browned and aromatic—this should only take a few minutes.
Step 4: Strain the finished soup broth into a large bowl and add the sautéed mushrooms.
Tip: I like to strain the soup directly into the skillet that I used to cook the mushrooms, then I can scrape up any browned, ultra-flavourful mushroom bits left on the bottom of the pan.
Step 5: Bring some water to a boil in a small pot and cook the udon noodles according to the package directions. Drain.
Step 6: Divide the cooked udon noodles among two soup bowls. Carefully pour the hot mushroom broth and sliced mushrooms over the noodles. Serve with diced scallions.
Make Ahead & Storage Tips
Udon noodle soup is typically best when it’s prepared and eaten soon after and this recipe is no exception. One workaround for this is doing the prep separately a day or two ahead of time (the mushroom broth and the sautéed mushroom caps) and then assembling the soup with freshly cooked udon when you’re ready to eat.
The mushroom stock (without noodles) can be frozen for up to 6 months.
What to Serve with Shiitake Mushroom Udon Soup
Recipe FAQs
Yes. This recipe for udon soup is low in fat and high in plant-based nutrients. To keep this soup’s sodium levels down, reduce the amount of salt and soy sauce called for (or use a reduced sodium soy sauce.)
I like to serve this soup with vegan salads, vegetable-based sides, as well as stir fried vegetables and tofu.
Udon is often healthier than ramen because it will typically have a lighter broth.
More Japanese Recipes
Recipe Card
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Shiitake Mushroom Udon Noodle Soup
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Ingredients
- ½ pound fresh shiitake mushrooms
- 1 small piece dried kombu
- 1 small yellow onion, sliced into quarters
- 2 cloves garlic, crushed
- 3 cups water
- 2 tbsp oil
- 1 tbsp soy sauce
- 1 tsp salt
- 2 scallions, diced
- 2 pieces inari aka marinated fried tofu skin *optional
- 2 packages udon noodles
Instructions
- Cut the stems off 1/2 pound fresh shiitake mushrooms and thinly slice the mushroom caps.
- Add the mushroom stems, 1 small piece dried kombu, 1 small yellow onion, sliced into quarters, 2 cloves garlic, crushed, and 3 cups water to a small stockpot. Bring to a simmer, then turn the heat down to maintain a low simmer for 30 minutes, or until the onion no longer smells raw.
- Meanwhile, heat 2 tbsp oil in a skillet on high heat and sauté the mushrooms until they are browned and aromatic—should take only a couple of minutes.
- Strain the soup into a large bowl and stir in the sauteed sliced mushrooms. (I strain the soup directly into the skillet so I can scrape up all the yummy bits of mushroom that have stuck to the skillet and incorporate them into the soup for more flavour.)
- Add 1 tsp salt and 1 tbsp soy sauce, plus more to taste.
- Return the empty stockpot to the stove. Bring some water to a boil and cook the 2 packages udon noodles.
- When noodles are done, drain them and divide them into two bowls. Pour over the mushroom broth. Top the bowls with 2 pieces inari aka marinated fried tofu skin and 2 scallions, diced.