This sweet potato and tofu udon is a simple yet satisfying noodle soup that can be thrown together quickly for an uncomplicated midweek meal comfort.
No muss, no fuss, this sweet potato and tofu udon is a simple yet flavorful weeknight option.
Cubed sweet potatoes soften in a savory dashi-based broth, adding a subtle sweetness that balances the salty depth of tamari and the nuttiness of sesame oil. With tofu for protein, Napa cabbage for a vegetal element, and bouncy, thick udon noodles, this soup is balanced and filled to the brim with all the best things.
If you’ve been looking for quick soups to add to your rotation this winter, make sure this one gets on the list. I love how easy it is to make while still feeling robust and flavorful.
This soup relies on dashi granules to do a lot of heavy lifting. This foundational Japanese broth is most commonly made from kombu (dried kelp) and, in traditional versions, bonito flakes. While you can easily make dashi broth from scratch using kombu and bonito flakes, I love keeping a jar of granulated dashi in my fridge for quick weeknight soups and broths (or even marinating meat with it). It brings a savory, somewhat briny umami flavor that makes the broth taste rich and complex without heaviness. In this soup, dashi plays well with the subtle, earthy sweetness of sweet potatoes.
As a note, dashi is traditionally not vegan or vegetarian as it contains bonito flakes. I’ve had success with this vegan dashi, but sometimes I have to add a little extra to get the flavor to shine through as it can be a little less salty and a bit less flavorful than traditional dashi.
How to make sweet potato and tofu udon
A simple one-pot broth paired with chewy udon noodles for an easy, comforting dinner.
What you need
- Aromatics: Neutral oil, yellow onion, fresh ginger, garlic
- Vegetables: Sweet potatoes, Napa cabbage
- Broth: Dashi granules, water, tamari, sesame oil, chili oil, salt
- Protein: Firm tofu
- Noodles: Frozen udon, though you can use ramen or soba instead
- For serving: Furikake or sesame seeds
How to make it
Step 1: Sauté the aromatics.
Heat the neutral oil in a large pot over medium heat. Add the onion, ginger, and garlic and sauté briefly.
Step 2: Add the sweet potatoes and dashi granules.
Add the cubed sweet potatoes and sauté for 1 minute. Sprinkle in the dashi granules and lightly toast them in the oil.
Step 3: Simmer the soup.
Add the water and tofu to the pot and bring to a boil. Reduce the heat to low and simmer until the sweet potatoes are fork-tender.
Step 4: Cook the udon.
While the soup simmers, bring a large pot of water to a boil. Cook the frozen udon according to the package directions. Drain and divide between four bowls.
Step 5: Finish the soup.
Stir the Napa cabbage into the broth along with the tamari, sesame oil, and chili oil. Simmer until the cabbage wilts. Taste and adjust seasoning as needed.
Step 6: Serve.
Ladle the hot soup over the udon noodles and finish with furikake or sesame seeds.
Storage and reheating
Store leftover broth and noodles separately in airtight containers for up to 3 days. Reheat the broth gently on the stovetop and add a splash of water if needed. Warm the udon briefly in hot water before serving to loosen the noodles.
FAQ
Can I make this fully vegan?
Yes, just be sure your dashi granules are vegan. Many brands offer kombu-based dashi with no bonito.
Can I swap the udon for another noodle?
Absolutely. Soba, ramen, or rice noodles all work well here; just cook them separately and add the broth at serving.
How spicy is this soup?
It has a very subtle heat as written. You can easily dial it up or down by adjusting the chili oil, or leave it out entirely for a gentler bowl.
Can I use meat instead of tofu?
Absolutely! Shred a rotisserie chicken for a super easy option. It would also be delicious with my sweet and spicy pork chops on top.
Sweet Potato and Tofu Udon
Equipment
Ingredients
- 1 tablespoon neutral oil
- 1 yellow onion (peeled and diced)
- 1-inch piece ginger (peeled and minced)
- 4 cloves garlic (peeled and minced)
- 1 pound sweet potatoes (peeled and cut into 1-inch cubes)
- 2 tablespoons dashi granules
- 6 cups water
- 1 pound firm tofu (cut into 1-inch cubes)
- ¾ pound Napa cabbage (roughly chopped)
- ⅓ cup tamari
- 1 tablespoon sesame oil (plus more to taste)
- 1 tablespoon chili oil (plus more to taste)
- Salt to taste
- Furikake (or sesame seeds for serving)
- 26 ounces frozen udon (see Note 1)
Instructions
Sauté the aromatics:
- Heat 1 tablespoon neutral oil in a large pot over medium heat. Add the onion, ginger, and garlic, and sauté for 3 to 4 minutes.
- Add the sweet potato and sauté for 1 minute. Season with the dashi granules and sauté for 1 to 2 minutes.
Simmer the soup:
- Add the water and cubed tofu to the pot. Bring to a boil. Reduce the heat to low and simmer uncovered for 30 minutes until the sweet potatoes are fork-tender. Taste and add a small pinch of salt if needed.
Cook the udon:
- Bring a large pot of water to a boil. Add the frozen udon and cook according to package directions. Drain and divide between four bowls.
Finish the soup:
- Add the chopped Napa cabbage to the pot along with ⅓ cup tamari, 1 tablespoon sesame oil, and 1 tablespoon chili oil. Simmer for 5 to 7 minutes until the cabbage wilts. Taste and adjust the seasonings to your preference.
To serve:
- Ladle the soup over the cooked udon and serve with sesame seeds or furikake. Enjoy!
