Miso-Butternut Squash Soup with Soba or Udon Noodles

This miso butternut squash soup has been a reader favorite on VegKitchen since 2018 - and it's just as cozy and satisfying as ever. We've given it a fresh update with brand-new photos, but the recipe is the same warming bowl we've always loved: a rich miso-ginger broth, tender squash, soba noodles, and a heap of wilted greens.

Key Ingredients & Substitutions

• Butternut squash. Roasted or microwaved until just tender - it adds natural sweetness and body to the broth. Kabocha squash or sweet potato work as swaps and cook in roughly the same time.
• Vegan miso paste. The soul of this soup. White (shiro) miso is mild and slightly sweet; yellow miso is a bit more savory; red miso is the boldest and most intense. Any variety works - just make sure it's labeled vegan, as some miso pastes contain dashi (fish stock). Stir it in at the very end, off the heat, to preserve its probiotic benefits.
• Soba noodles. Buckwheat soba gives the soup its earthy, nutty character. Pure buckwheat soba is also gluten-free - just check the label, as many commercial soba blends include wheat flour. Udon noodles work equally well for a thicker, chewier texture.
• Fresh ginger. Grated fresh ginger is essential here - it adds warmth and brightness that ground ginger can't replicate. Use as much as you like.
• Vegan vegetable bouillon cubes. Two cubes give the broth depth and savory umami to complement the miso. Choose a low-sodium, MSG-free brand. Vegetable broth works as a direct substitute - just use it in place of the water.
• Baby spinach. Stirred in at the end, it wilts in about a minute and adds color and nutrition. Watercress, baby arugula, baby bok choy, or any tender Asian green are excellent alternatives.
• Frozen peas. A simple addition that adds sweetness, color, and a little extra protein. Thaw them before adding so they don't drag down the broth temperature.

Variations

• Make it brothier. This soup is fairly thick as written. For a more broth-forward bowl, increase the water to 6 cups and add an extra bouillon cube.
• Add tofu. Cube a block of firm or extra-firm tofu and add it with the squash for extra protein. Press it first so it holds its shape in the soup.
• Spicy miso version. Stir a teaspoon of sriracha or a pinch of red pepper flakes into the broth along with the miso for a warming kick.
• Add edamame. Swap the peas for shelled edamame (thawed from frozen) for higher protein and a slightly nuttier flavor.
• Rice noodle version (gluten-free). Use thin rice noodles in place of soba. Soak them separately according to package directions, then add to bowls when serving to keep them from absorbing all the broth.
• Richer broth. Stir in a tablespoon of tahini or a drizzle of toasted sesame oil just before serving for a creamier, nuttier finish.

Tips for the Best Miso Butternut Squash Soup

• Never boil miso. Always dissolve it in warm (not boiling) water and stir it in at the very end with the heat off or very low. Boiling destroys the beneficial probiotics and dulls the flavor.
• Cook the squash just until tender. You want it to hold its shape in the soup, not turn to mush. Whether you're microwaving or roasting, test it with a knife - it should pierce easily but still feel firm.
• Cook noodles separately if making ahead. Soba absorbs broth quickly as it sits. If you think you'll have leftovers, cook the noodles separately and add them to individual bowls at serving time.
• Taste and adjust the miso at the end. Start with 2 tablespoons, then add more to taste. The amount you need depends on the brand and type of miso - some are much saltier than others.
• Prep the squash ahead. The squash can be cooked, peeled, and cubed up to 2 days in advance and kept in the fridge. It makes this a genuinely quick weeknight soup.

How to Serve

Serve immediately in deep bowls with chopsticks for the noodles and a spoon for the broth. This soup is a complete meal on its own but pairs beautifully with a simple cucumber salad, edamame, or steamed dumplings. For a heartier spread, serve alongside brown rice or a wedge of crusty sourdough bread. Leftovers keep for up to 3 days in the fridge - store the noodles and broth separately if possible, and reheat gently over low heat without boiling. For another light and healthy vegan soup, try our yellow squash soup, our cream of asparagus soup, or our fresh tomato and corn soup. For a hearty butternut squash dinner, our creamy butternut squash pasta casserole is wonderfully satisfying.

Recipe

Miso Butternut Squash Soup with Soba Noodles

5 from 20 votes

A warming, deeply savory vegan noodle soup built on a miso-ginger broth with tender butternut squash, soba noodles, spinach, and peas. Quick to pull together once the squash is cooked — and beautiful in the bowl.

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Prep Time: 15 minutes minutes

Cook Time: 25 minutes minutes

Total Time: 40 minutes minutes

Servings: 6 servings

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Ingredients

• 1 small butternut squash about 1 pound
• 4 cups water plus more as needed
• 4 ounces soba (buckwheat) or udon noodles broken in half
• 2 teaspoons fresh ginger grated, or more to taste
• 2 vegan vegetable bouillon cubes low-sodium, no MSG
• 4 ounces fresh baby spinach about 4 to 6 cups loosely packed
• 1 cup frozen green peas thawed
• 3 scallions thinly sliced
• 3 tablespoons vegan miso paste white, yellow, or red — see notes
• freshly ground black pepper to taste

Instructions

• Pierce the butternut squash a few times with a knife. Microwave on high for 4 to 6 minutes, adding 1 minute at a time, until it can be pierced easily with a knife but still holds its shape. Alternatively, wrap the whole squash in foil and bake at 375°F for 30 to 40 minutes until just tender. Let cool until easy to handle, then halve, scoop out the seeds, peel, and cut the flesh into bite-sized chunks. Set aside. (This step can be done ahead of time.)
• Bring the 4 cups of water to a rapid simmer in a large soup pot. Add the soba or udon noodles and cook according to package directions until al dente, about 4 to 5 minutes.
• Add the grated ginger, bouillon cubes, thawed peas, and squash chunks to the pot. Stir to dissolve the bouillon and cook for 3 to 4 minutes over medium heat. Add up to 1 cup additional water if the soup seems too thick.
• Stir in the spinach and cook just until wilted, about 1 to 2 minutes. Add the scallions and stir to combine.
• In a small bowl, whisk the miso paste with ⅓ cup warm (not boiling) water until smooth. Stir into the soup. Taste and add more dissolved miso if desired — do not boil the soup after adding miso, as heat destroys the beneficial probiotics. Season with black pepper and serve immediately.

Notes

Choosing miso: Use white (shiro) or yellow miso for a milder, sweeter flavor; red miso for a more intense, earthy broth. Always check the label — some miso pastes contain dashi (fish stock) and are not vegan. Look for miso labeled vegan or check that the ingredients list only soybeans, salt, and grain (rice or barley).

Soba noodles: Pure buckwheat soba is gluten-free, but many commercial soba blends contain wheat flour — check the label if gluten is a concern.

Greens variation: Watercress, baby arugula, chopped baby bok choy, or other Asian greens all work beautifully in place of or alongside the spinach.

Make ahead: Cook the squash up to 2 days in advance and refrigerate. The assembled soup is best eaten fresh — the noodles will absorb the broth on standing.

Vegan-ize any recipe!Grab our free vegan cheat sheet, packed with my favorite easy substitutions to make any recipe vegan.

Also try: our creamy asparagus and pea pasta.