Portobello Pot Roast (Vegetarian!)

This Vegetarian Portobello Pot Roast recipe can be made easily in the slow cooker or Instant Pot (pressure cooker).  And it’s SO hearty and comforting and delicious!

Vegetarian Portobello Pot Roast Recipe

As a Midwestern girl through and through, I’ve gotta admit — I will always love me a good pot roast.

But hey, whoever said that had to include roast beef?  😏


A few weeks ago, when I found myself with two leftover cartons of baby bella mushrooms in the fridge that needed to be used up stat, I decided to try swapping them in as the main ingredient in my traditional pot roast recipe.  And lo and behold, they turned out to be a plant-based swap made in heaven.

This vegetarian pot roast recipe was a total winner, guys!

It’s still full of those classic savory flavors (and garlicky gravy!) that we all love.  It’s quick and easy to prep, and easy to make either on the stovetop or in the slow cooker or Instant Pot.  It’s naturally vegetarian, vegan, and gluten-free.  And it’s totally, wonderfully delicious.

My kind of comfort food.  💛

Mushrooms for this Vegetarian Portobello Pot Roast Recipe

To make the recipe, start by gathering lots of your starring ingredient — portobello mushrooms.  💛  You’re welcome to use full-size portobellos if you’d like.  Or, you can be like me and just use a few cartons of baby bellas.  Chop them up into bite-sized pieces…

Vegetarian Portobello Pot Roast Recipe Ingredients

…then combine them in a slow cooker or pressure cooker, along with some potatoes, carrots, pearl onions, garlic, and all of the ingredients for that classic savory gravy.  Cook until the potatoes are nice and tender.  Then for a final step, thicken that gravy up a notch…

How To Make Portobello Pot Roast (Vegetarian / Vegan / Gluten-Free)

…and voila!  This delicious veggie-filled mushroom pot roast will be yours to serve and enjoy!

Vegetarian Portobello Pot Roast Recipe with noodles

I went old-school and served mine over some egg noodles, but some grains or rice would also work well here.  I served mine up with this simple salad and some red wine, and the meal was perfection. 🌟🌟🌟

Vegetarian twist for the win!

5 / 5 (10 Reviews)
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Vegetarian Portobello Pot Roast

This vegetarian Portobello Pot Roast recipe is quick and simple to prep, easy to cook in the Instant Pot or slow cooker, and it’s full of the classic savory flavors we all love!


  • 1.25 pounds Yukon gold potatoes, cut into bite-sized pieces
  • 1 pound baby bella mushrooms (if they are large, cut them in half)
  • 2 large carrots, peeled and cut into bite-sized pieces
  • 2 cups frozen pearl onions*
  • 4 cloves garlic, peeled and minced
  • 3 sprigs fresh thyme
  • 3 cups vegetable stock, divided
  • 1/2 cup dry red or white wine
  • 3 tablespoons tomato paste
  • 2 tablespoons (vegetarian**) worcestershire
  • 2 tablespoons cornstarch
  • Kosher salt and freshly-cracked black pepper
  • optional garnish: finely-chopped fresh parsley


Slow Cooker Method:

  1. Add potatoes, mushrooms, carrots, onions, garlic, thyme, 2.5 cups vegetable stock, wine ,tomato paste and worcestershire together in the bowl of a crock pot, and gently toss to combine.  Cook on low for 6-8 hours, or on high for 3-4 hours, until the potatoes and carrots are tender.
  2. In a separate bowl, whisk together the remaining 1/2 cup vegetable stock and cornstarch until combined.  Add to the roast mixture, and gently toss to combine.  Continue to cook for 1-3 minutes, until the sauce thickens up a bit.
  3. Serve immediately, garnished with fresh parsley if desired.

Instant Pot Method:

  1. Add potatoes, mushrooms, carrots, onions, garlic, thyme, 2.5 cups vegetable stock, wine and worcestershire together in the bowl of a pressure cooker, and gently toss to combine.  Close lid securely and set vent to “Sealing”.
  2. Press “Manual”, then press “Pressure” until the light on “High Pressure” lights up, then adjust the up/down arrows until time reads 20 minutes.  Cook.  Then let the pressure release naturally, about 15 minutes.  Carefully turn the vent to “Venting”, just to release any extra pressure that might still be in there.  Remove the lid.
  3. In a separate bowl, whisk together the remaining 1/2 cup vegetable stock and cornstarch until combined.  Add to the roast mixture, and gently toss to combine.  Continue to cook for 1-3 minutes, until the sauce thickens up a bit.
  4. Serve immediately, garnished with fresh parsley if desired.

*Feel free to sub in sliced white onions, if pearl onions are not available.

**If making this recipe vegetarian, use vegetarian Worcestershire.

***Cook time listed above is for a slow cooker set on “high”.

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If you make this recipe, be sure to snap a photo and hashtag it #gimmesomeoven. I'd love to see what you cook!

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23 comments on “Portobello Pot Roast (Vegetarian!)”

  1. This looks absolutely delicious…do you think it would work out to halve the recipe? Very small family, it would be too much for us.

  2. I can’t wait to try it out!

  3. WOW! This sounds so good! I’m going to have to try it. Friendly suggestion to those who may try this: Try to use NON-GMO corn starch.

    Thank you so much for sharing this.


  4. Oh yummm this looks DELICIOUS and I feel I won’t even miss the meat! My BF and I have been vegan/plant based diet since July and I am excited to try all the warm/cozy winter meals – this one is definitely going to be tried! YUM!

    Rating: 4
  5. As soon as this hit my email I started craving it. Had it for dinner tonight and it was sooo good! My husband had 3 bowls. Can’t wait for my lunch leftovers tomorrow

    Rating: 5
  6. Made this tonight (added beef for my carnivorous hubby) but it was absolutely delish! Over the weekend I made your slow cooker chili and the coconut oil pumpkin bread, everything was amazing!
    Thank you for creating recipes with easy to get ingredients, easy to follow instructions and wonderful results!

    Rating: 5
  7. Hey! I made a half batch of this in the Instant Pot, and my carnivore husband was in heaven! I used the saute function when I added the cornstarch and broth and the sauce bubbled and thickened beautifully.

    Just wanted to suggest that you note that traditional Worcestershire sauce is not vegetarian or vegan as it contains anchovies. Your veggie readers like me would know that – and there are vegetarian Worcestershires available – but I could see a well-intentioned omnivore making this to serve to others without knowing that.

    Rating: 4
  8. Delicious & I didn’t miss the meat at all! I did transfer to a pan and thickened on the stove top.

    Rating: 5
  9. This sounds great and I just happen to have two packages of baby bella mushrooms in my fridge right now, so I will be making this tonight. Just curious, do you prefer using red or white wine in this??

  10. It was wonderful! Made it for meatless Monday and I will definitely make it again. Appreciate the Insta Pot instructions, thank you!

    Rating: 5
  11. Really good flavor but mine came out so soupy and nothing like the pictures! What did I do wrong?! I want to get that nice glaze on the veggies like you have in the pictures

    • Mine too! Taste was great but liquid never thickened. Followed instant pot directions.

      Rating: 4
  12. Quick question…how would I cook this on the stove?

    Thanks! :)

  13. Hi, I love your blog! I wanted to know if there was a substitute for the wine in this recipe? I don’t cook with it for religious purposes. Your feedback would be appreciated.

  14. Listen girl, can I just say, as a fellow food blogger, you have mastered taking pretty pictures with food in a crock pot. MASTERED. Finally, I can see that I need to slay down a white background to make it pop. thank you!!!

  15. This is Delicious! Don’t miss the meat at all. Used baby carrots.

    Rating: 5
  16. My wife made this tonight and it was delicious. I do wish the portion size and calories were included for us that are counting calories.

    Rating: 5
  17. Making this right now! Wondering if it freezes well??

  18. This is delicious! I added frozen peas at the end and heated until they thawed. The first time, I served it over noodles; the second, over polenta that I had pan fried. Both ways we’re great. Love this dish!

    Rating: 5
  19. What size crock pot can you use? I have a small (3.5qt) pot