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!

Vegetarian Portobello Pot Roast Recipe

Vegetarian Portobello Pot Roast

  • Prep Time: 10 minutes
  • Cook Time: 240 minutes
  • Total Time: 250 minutes
  • Yield: 6 -8 servings 1x


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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38 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. 4 stars
    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!

  5. 5 stars
    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

  6. 5 stars
    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!

  7. 4 stars
    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.

  8. 5 stars
    Delicious & I didn’t miss the meat at all! I did transfer to a pan and thickened on the stove top.

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

  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

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

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

  16. 5 stars
    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.

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

  18. 5 stars
    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!

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

  20. 5 stars
    I just made this and it was so good! My grocery store was out of baby bellas so I had to use sliced. Otherwise I followed the Instant Pot instructions exactly. Mine came out pretty soupy but I think it may have been because of the sliced mushrooms. Next time I would do maybe 1.5 or double the mushrooms. We served this over a wild rice blend and between the two of us my boyfriend and I ate about half the recipe! I’m vegetarian and he’s not and we both loved it!

  21. Followed instructions EXACTLY. Turned out very bland and watery. Would not recommend at all. Very disappointed.

  22. 4 stars
    Definitely good for something different. I did feel like a missed the meat a tad bit. Might make it again using a small amount of beef and a little less liquid. I subbed broth for the wine since I have young kids.

    As one of the posters suggested, I did hit the saute button on my instant pot to help thicken it. It was a little soupy. My veggies were cut small and a little overcooked so I also might cook a little less next time.

    Thanks for sharing.

  23. 5 stars
    OMG this is incredible. Even my 15 year old non-vegan was asking for more. Hearty and delicious! Make some great bread, ad something green like a salad and you are in business! Will definitely make this again and again1

  24. 5 stars
    Made this last night. We are omnivores – We LOVED this meal. Definitely a do again in our household

  25. 4 stars
    I had the same experience as a few others, the sauce turned out thin. I added about 1/3 cup of nutritional yeast which thickened it right up

  26. I just cooked on stove top for about 2 hours. Got rave reviews. I didn’t have worchestersire sauce but used Pick-a-Pepper.

  27. 5 stars
    I am new to vegetarian and finding replacements for those favorite comfort foods has been a challenge. Thistle recipe was spot on, thick gravy, plenty of veggies, very filling. Made in instant o, so simple. This will for sure go into the rotations.

  28. What can I use as a substitution for the Worcestershire sauce?

  29. 5 stars
    Very easy to make. My guests and I loved it. Amazing flavor!

  30. 4 stars
    I made this dish for a meal train. I used vegan creamy vegetable stock instead of regular vegetable stock, fresh pearl onions instead of frozen and I added a little more garlic. The flavor was really good and the vegetables were perfectly cooked. I will make it again for my family with a few changes. I would NOT use the vegan creamy vegetable stock again because the appearance of the sauce was so unappetizing. Also, I would increase the amount of mushrooms to 1.5 or 2 pounds. Here is what I did to thicken up the sauce: I placed the 1/2 cup stock and corn starch in a medium/small sauce pan (do not turn on). Once the InstaPot was vented, I poured the liquid from the InstaPot into the sauce pan. Turned on the burner under the saucepan and heated it until it reached my desired thickness (stirring constantly). Then, I poured it back over the vegetables. Yummy!

  31. 5 stars
    Absolutely loved this recipe. Making it again but have added soaked, dried shitake mushrooms and some beautiful oyster mushrooms for some added texture and extra umami. Thanks

  32. I don’t use alcohol. Any substitution suggestions?

  33. 5 stars
    Recipe is perfect! However, I did substitute 1.25 pounds of peeled and diced rutabagas and turnips for the potatoes since I do not eat potatoes. I also added some chopped celery. Skipped the wine and Worcestershire sauce but used low sodium veggie broth and it was perfect. Thank you for a great recipe.

  34. Delicious! even with some accidental changes! i didn’t have wine or corn starch, so i skipped the wine and used a little flour. was delicious out of the pot, BUT i have an addiction to white pepper so i added a little and it was just the thing for me. excited to try prior reviewer’s suggestion for rutabaga and turnip, may also replace carrot with parsnip and see how that goes. great recipe that seems to have great flexibility! thank you!