Instant Pot Vegetable Pho Noodle Soup starts with a delicious, from-scratch broth. This soup is healthy and packed with flavor.
ALLERGIES: the only thing I don’t like about Spring. This whole week, I’ve felt like I have three faucets where my eyes and nose should be.
What I’m getting at is that this is a perfect opportunity to consume massive amounts of warming, delicious, healthy soup. Like PHO! I’m an absolute pho fanatic. This vegetarian pho recipe is loaded up with vegetables and herbs. It’s the perfect bowl when you’re under the weather!
Making Instant Pot Vegetable Pho Noodle Soup
You could make an incredibly fast, easy vegetable pho soup using high-quality vegetable stock from the grocery. But it’s so easy to make your own (much better) vegetable stock in the Instant Pot! Plus, it gives you the perfect opportunity to use up your vegetable scraps.
I always have vegetable odds-and-ends in my crisper and freezer. For example, mushroom stems, a quarter head of cabbage, half an onion, and the like. I also freeze broccoli stems and the the green portion of any leeks I buy for exactly this purpose.
For this recipe, I used fresh and dried mushrooms (stems and all), celery, carrots, sweet onions, ginger, and garlic.
If you have vegetable scraps to use up, by all means add them in!
Building flavor into your Instant Pot Vegetable Pho
The first key to a rich, deeply flavorful vegetable stock is to caramelize the onions. You can do this using the Instant Pot’s saute function (I use the highest setting). Add olive oil to the insert of the Instant pot, then add in your onion and fresh mushrooms. We want the onion and fresh mushrooms to be dark brown—practically charred—in a few spots (it doesn’t need to be even; photo 2. in the collage below shows onions that aren’t quite as brown as I like them for this stock).
Add the water for the stock (8 cups) to deglaze, scraping the bottom of the insert with a wooden spoon to loosen any browned bits, which are GOLDEN for flavor building.
Using dried mushrooms is also essential to a richly flavored stock. I like a combination of dried shiitake and wood ear mushrooms.
Finally, several dashes of Maggi seasoning sauce (or use liquid aminos, which is the base for the vegan version of my Quick Nuoc Cham Sauce) adds umami and salt.
I don’t add salt to this soup: the Maggi seasoning sauce and the nuoc cham I use for garnish are plenty salty. Plus, canned straw mushrooms are typically stored in brine (if you’re on a salt-restricted diet, be sure to rinse them well).
Pressure cooking the stock
Add the remaining vegetables and seasonings to the insert of the Instant Pot. Close the lid and seal the valve. Press “Pressure Cook.” The stock should cook on high pressure: if “High Pressure” is not selected, press “Pressure Cook” again (see photo 4. below). Use the plus button to adjust the cooking time to 30 minutes.
After a few seconds, the pot will begin to pressurize. When the cooking time is complete, let the pressure release naturally (don’t open the valve). Note that it takes around 10 minutes for the pot to come to pressure, and as much as 25 minutes to depressurize.
I use the pressure cooking time to prep the vegetables for the final soup (photo 5. below).
Once the Instant Pot has depressurized, press “Cancel.” Fish the solids out of the stock with a skimmer. Remove the solids to a colander set into a bowl and give them a rinse (with about 2 cups of water). Then, squeeze the mushrooms to get as much liquid out as possible. Discard the solids and add the rinsing liquid back to the Instant Pot.
Run the stock through a fine-mesh strainer. Rinse and wipe out the insert of the Instant Pot, then replace in the cooker. Return the stock to the insert. Press “Saute” and choose the highest setting. Simmer the stock with sliced onions and cilantro stems for 10 minutes (meanwhile, prepare the pho noodles according to package directions).
Next, add the sliced mushrooms and broccoli florets. Simmer for 5 minutes. Add the remaining vegetables and simmer long enough to soften up the baby bok choy and warm everything through, about 3 more minutes.
Finally, divide the noodles among four bowls, add the stock and vegetables, and let everyone top with their favorite garnishes and sauces.
Vegetable options for Instant Pot Vegetable Pho
This soup is LOADED with vegetables. You can’t have too many, IMO. Well…I suppose you can. Just make sure that you have a good stock-to-veggie ratio, and your soup will be delicious. You can also go lighter on the veggies, if that’s your preference.
For this recipe, I used broccoli florets, sliced zucchini, lots of fresh and canned mushrooms, and baby bok choy. But the soup is really quite versatile. You can use sliced cabbage, if that’s what you have on hand. You could add spinach just before serving. Fresh green beans would be a lovely addition.
If you’re not a fan of the mushrooms, you can leave them out and add more green vegetables (but don’t skip the dried mushrooms in the stock!).
The pho bowl that inspired this dish (at a pho joint near Green Bay, Wisconsin) had a lot of baby corn. I don’t care for that flavor, though, so I left baby corn out of my vegetarian pho recipe. If you like it, absolutely add it back in. (Personally, I’d rather use fresh sweet corn kernels.)
You can also adapt the vegetable pho soup to whatever veggies are in season.
My must-have garnishes are sliced jalapeños, sliced scallions, cilantro, Thai basil, and lime wedges. Mung bean sprouts are also wonderful. Sriracha is also a must, as is my Quick Nuoc Cham Sauce (use the veganized version).
That’s it! I hope you love this healthy, delicious soup. If you’re a pho fanatic like me, be sure to check out my other pho recipes: Pressure-Cooker Pho Ga, Slow-Cooker Rotisserie Chicken Pho Ga, and Slow-Cooker Duck Pho. I have several more versions planned, so stay tuned!
Instant Pot Vegetable Pho Soup
FOR THE STOCK (see Recipe Note #1)
- 2 tbsp olive oil - extra virgin
- 1 medium sweet onion - cut into quarters
- 5 whole star anise pods
- 1 tbsp fennel seeds
- 1 tbsp coriander seeds
- 1 cinnamon stick
- ½ tbsp whole black peppercorns
- 1 cup mixed dried mushrooms - (I like shiitake and wood ear)
- 1 1-inch cube of ginger - peeled
- ½ tsp Maggi Seasoning Sauce - (see Recipe Note #2)
- 2 celery stalks
- 8 baby carrots
- ½ cup fresh parsley
- 3 garlic cloves - unpeeled
- 2 bay leaves
- 2 kaffir leaves - (also called lime leaves; optional)
FOR THE SOUP
- 1 medium sweet onion - cut into thin quarter rings
- 2 tbsp cilantro stems - finely chopped
- 2 cups broccoli florets
- 8 oz shiitake mushrooms - stemmed and sliced
- 1 can straw mushrooms - drained
- 1 small zucchini - halved and sliced ~¼" thick
- 2 cups baby bok choy - sliced ~¼" thick
- cilantro - chopped
- Thai basil leaves - whole (tear over individual servings of soup)
- scallions - sliced
- jalapeños - sliced
- mung bean sprouts
- lime wedges
- Nuoc cham sauce - (see Recipe Note #3)
FOR THE STOCK
- Press the Instant Pot's saute button until the highest setting is selected. Add olive oil to the insert of the Instant pot, then add in the quartered onion. Saute until dark brown—practically charred—in spots, about 5 minutes. Add the anise pods, cinnamon stick, fennel seeds, coriander seeds, and black peppercorns. Continue to saute for an additional 2 minutes. Press "Cancel" on the Instant Pot's control panel.
- Add 8 cups of water to the insert of the Instant Pot; use a wooden spoon to scrape up any browned bits on the bottom. Add the remaining ingredients for the stock. Close the Instant Pot's lid and seal the valve. Press "Pressure Cook" so that the highest setting is selected. Use the "+" button to adjust the time to 30 minutes. When the cook cycle is finished, allow the Instant Pot to depressurize naturally, about 25 minutes (or until the float valve drops).
- Once the Instant Pot has depressurized, press "Cancel." Twist open the valve and then the lid. Fish the solids out of the stock with a skimmer and remove to a colander set into a bowl. Rinse with 2 cups of water. Squeeze the mushrooms to get as much liquid out as possible. Discard the solids and add the rinsing liquid back to the Instant Pot. Run the stock through a fine-mesh strainer and into a bowl.
FOR THE SOUP
- Rinse and wipe out the insert of the Instant Pot, then replace in the cooker. Return the stock to the insert. Press "Saute" and choose the highest setting. Simmer the stock with sliced onions and cilantro stems for 10 minutes (meanwhile, prepare the pho noodles according to package directions). Next, add the sliced mushrooms and broccoli florets. Simmer for 5 minutes. Add the remaining vegetables and simmer long enough to soften up the baby bok choy and warm everything through, about 3 more minutes (see Recipe Note #4).Finally, divide the noodles among four bowls, add the stock and vegetables, and let everyone top with their favorite garnishes and sauces.
- You can use store-bought vegetable stock, but I do advise simmering first (about 15 minutes) with some star anise, cinnamon stick, fennel seeds, and coriander seeds to give it the proper pho flavor.
- For gluten-free, use a tablespoon of liquid aminos instead.
- Use the veganized version of my Quick Nuoc Cham Sauce.
- Add your vegetables to the Instant Pot according to the amount of time they'll need to simmer (you want your veggies to be crisp tender).
- The stock can be prepared in advance. Keep refrigerated in an airtight container for up to 3 days.