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Portobello Pot Roast (Vegetarian!)

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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!

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 and vegan. 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!

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Vegetarian Portobello Pot Roast Recipe

Vegetarian Portobello Pot Roast

5 Stars 4 Stars 3 Stars 2 Stars 1 Star 4.3 from 60 reviews
  • 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 sauce*
  • 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, tomato paste 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.


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

Worcestershire: If making this recipe vegetarian, be sure to use vegan Worcestershire sauce.

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

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

  1. I’ve tried making this several times, and every time it comes out VERY different than the picture. (Doesn’t everything”)
    Our sauce seems so much thinner than what is pictured and everything comes out mushy when cooking exactly as the recipe suggests for the InstantPot. Tonight, I tried cooking at 14 minutes instead of 20, and it’s better but still mushy. I really don’t know what I’m doing wrong. I was really looking forward to this. Maybe I’m expecting too much of myself. The flavor is good, albeit a little bland. But overall, the dish is delish.

    • Ours also came out very different than the picture – thin sauce (almost like soup). The potatoes and carrots were super soft, but the mushrooms still had a bite. Flavours were blander compared to what we’re used to, but since we’re also making this for baby, it’s in a way perfect. Had to split it in 2 batches to do it in our 6qt Instant Pot. Next time, we’ll keep 1 batch the same for baby and experiment with different spice/herb combos for the other batch. All in all, it’s a great basic veggie loaded recipe that we’ve been needing.

    • I don’t feel like this recipe works very well for the instant pot unfortunately. The flavors were kinda underdeveloped, the sauce was thin even with the addition of cornstarch, the potatoes were mushy.. I could see it being better in the slow cooker maybe. Gonna try another recipe next time.

  2. This was delish! Made it last night (Instant Pot version) and was extremely hopeful that the results tasted as good as it looked. I was not disappointed in the least. Reheated it for lunch today. Definitely a 5-Star keeper even with me forgetting the wine, Worcestershire and tomato sauce and using “Better than Bouillion Organic Chicken Base” in lieu of vegetable stock. Next time, I’ll add missing ingredients as well as chopped bell peppers and celery sauteed along with the onions. Believe me, whatever you’d add to your pot roast can be added to this. You won’t be disappointed either nor will you miss the meat.

  3. Do you have nutrition information available?

  4. I see where the ingredients list says 6 cups vegetable broth divided…then only 2.5 cups added to the crock pot plus the other half cup to mix with cornstarch. When do you use the other 3 cups of vegetable stock? Am I missing something?

    • I see now that the recipe has been changed to 3 cups…Thanks!

    • I made this for dinner tonight and appreciate the recipe! The wine made the stew a little too bitter, so I added some butter to balance it out. I also found the stew bland for my taste, so I added some extra seasonings. Helped the flavor out alot. Overall, I am glad that I tried it:)

  5. Nutrition Facts
    Serving size: 1 cup
    Servings: 7
    Amount per serving
    Calories 90
    % Daily Value*
    Total Fat 1.1g 1%
    Saturated Fat 0.9g 5%
    Cholesterol 0mg 0%
    Sodium 338mg 15%
    Total Carbohydrate 17.6g 6%
    Dietary Fiber 2.6g 9%
    Total Sugars 4.9g
    Protein 3g
    Vitamin D 0mcg 0%
    Calcium 27mg 2%
    Iron 1mg 6%
    Potassium 626mg 13%

  6. Tried this out today for something warm and cozy. Made a few changes as ingredients were limited (especially during this crazy time). Used sliced fresh yellow onions, frozen sliced carrots, used dried basil and parsley, and instead of cornstarch I used unflavored pea protein powder. Which not only thickens it up but ups the protein. And served it with chickpea pasta. It was delicious!!

    • Hi! I don’t have any extra cooking machinery, could I attempt this on a stove? I’ve never used an instant pot or slow cooker and I’m not sure how to change the cooking times or method! Thanks for any help

    • Pea protein powder? Could you taste it ?

  7. Does this freeze well?

    • Hi. Potatoes don’t freeze very well. They become grainy and mealy when defrosted. I’ve tried a few times myself with bad results. You might want to decrease the recipe if you can’t finish it all in a week.
      I double checked on Google and they confirmed it.
      Stay healthy

  8. how much does all of this cost

  9. no tomato paste in the instant pot version?

  10. Fair recipe. The instant pot directions are missing when to add tomato paste, mushrooms should all be cut in half at least, keep potato pieces fairly large, add frozen peas once it’s cooked, and pressure should be released after 15 minutes of natural release to avoid mushiness.

  11. This was tasty! I made the instant pot version and it did turn out a bit soupy for me, but we used a slotted spoon and ate over brown rice and it was good. Next time I would probably use a bit less broth. The mushrooms were delicious, this is a great concept.

  12. Looks wonderful! Making out my grocery list for this now.

  13. I’ve been vegetarian for most of my life. I like to cook pot roast for my husband when the weather gets cold. I love the smell, especially in the winter. Who would have guessed that I can make a decent substitute we both can eat out of baby Bella mushrooms? Made it today in the crockpot, and followers the recipe with just a few minor changes- no big carrots, so used a bag of baby carrots, used baby potatoes, halved, two boxes of baby Bella’s, and a jar of pearl onions (my only mistake -next tome I will use fresh onion…the jarred version taste pickled and are not a good sub for the frozen or fresh that the recipe called for). The liquid broth /sauce with the garlic, tomato paste, Worcestershire sauce and red wine was sublime. It had a complex, “beefy” flavor that smelled and tasted delicious. We are ours over a quinoa rice blend. I will definitely make it again. Thank you for the recipe!

  14. I love this recipe. It is comforting and delicious on a cold day. I have found that 12 minutes in the IP is perfect and I needed a little more cornstarch to thicken up the 2-1/2 cups of broth I used. I did not use 3 cups. Our garden yielded so much zucchini I added that in as well. We have had this with crusty bread and over noodles and each way is great. Thank you for sharing this recipe.

  15. Overall taste is good but definitely a little bland. Am going to try adding red pepper flakes and maybe some cheese (because who doesn’t love cheese?) to add to the flavor. Probably will not make again though.

  16. Just not what l was expecting. It smelled hearty but tasted bitter
    I’d omit the wine if l were to make it again

  17. What could I sub for the wine?

  18. This is a very tasty fall stew. I added some fresh rosemary, 3 stalks of celery, frozen green beans and peas. Made 12 servings for 3 families for Meatless Monday. Full of flavor. Soul satisfying. Nirvana in a bowl.

  19. This is incredible! Subbed stock for wine and omitted then cornstarch step. Made it in the instant pot. Carnivore approved!

  20. Now that the fall is here, I make this delicious recipe once a week for my family. It is so hearty and comforting. After making it a few times, I have found I enjoy a thicker “gravy” and will add much more cornstarch to the veggie stock when it’s time. I also add a bit more onions, garlic, and Worcestershire as well as thyme. I make it in the Instant Pot and it is perfect every time. Chop everything & sit back while it cooks!! Such a great weeknight meal!

  21. Can we use the instant pot instead? I love it and rather use it. Thanks

  22. What size crock pot is this recipe designed for?

  23. Love the idea of this recipe! My sauce is super thin though, looks like everyone has had different experiences. Mine is more like a soup…. it’s still good! I had more things to make a little more spicy.

  24. I love the vegetables in a pot roast,my mom made it every Sunday. Since I don’t “do” meat anymore,I was wondering how to achieve that taste with just veggies and the mushrooms are a BONUS! Thanks to the Google one never has to wonder any longer! Thank YOU for creating this recipe!

  25. Made the instant pot version and it was a total train wreck. Came out as a stew and nothing like a pot roast, followed the instructions to a T. The potatoes are completely overcooked and mushy. Maybe but slow cooker version is better, but this wasn’t great at all.

  26. Made this last night and even my skeptical husband liked it! Based on the comments, in the instant pot I used only 1 cup of broth for 12 minutes and everything was cooked perfectly. Served with egg noodles and it tasted like the Midwest.

  27. Do you need to stir the mixture at any point when using the slow cooker?

  28. When to add salt & pepper? How much each?

  29. I had same issue as everyone! This was so bland. Probably b/c all it had was thyme and garlic. (and salt and pepper). I did the slow cooker version, followed everything, mine also came out liquidy and more like a stew. I think this photo might be food photography and not representative of the true recipe. Would not recommend and won’t be making again. So disappointing as I was excited to find this recipe :(

  30. Great Vegan/Vegetarian dish. I made this dish using the instant pot method. I used 2 cups of unsalted vegetable broth And added 1 envelope of Mrs. Dash pot roast seasoning. (Amazon) I also did not add in the Worcestershire sauce. I wanted to make this recipe as low sodium as possible. (Yes, there are unsalted brotha in the grocery stores. Usually on the bottom shelf.)
    I served this over quinoa And tomorrow I will Put the mushroom pot roast mixture in a tortilla wrap. I made my gravy thick by using the saute and mixing corn starch with a little bit of unsalted vegetable broth add it to the mushroom mixture stir and let it saute in the instant pot for a few minutes until it thickens.

  31. Holy COW!!! No pun intended. This is awesome!!! Made it with no wine and only 2 1/2 cups broth. Just like the picture. Wish I could post mine. It is wonderfully rich in flavor.

  32. I can’t find one single vegan portabello mushroom pot roast that does not include wine. I don’t like/want wine in my recipe. Any help?

  33. I made this recipe as written with the exception of substituting a yellow onion for the green onions. I cooked it in the crock pot, and it was a little runny, as some other Reviewers have mentioned. I took some of the broth from the dish, added about 2-3 T of corn starch (in addition to the amount listed in the recipe). Whisked it, added back to the pot and cooked it a bit longer. It turned out perfect, looked like the photo, and most importantly, was delicious!

  34. This was delicious. After reading the comments I adjusted cook time in IP to 12 minutes and decreased broth to 2 cups. Next time I’ll prob decrease to 1.5 cups. I did not add more broth at the end, I took liquid out of the pot and added 4 tbs cornstarch. It was perfect with some extra time on warm and these adjustments

  35. I made this recipe but I didn’t have some of the ingredients so I substitute it apple cider vinegar for white wine and soy sauce for Worcestershire sauce and pureed tomatoes for tomato paste but I thought it was delicious and I cooked it in a regular pot my crock pot was too small and looking at some of the other comments added more cornstarch.

  36. My brother-in-law made this recipe for me. Although his method, for some reason, came out more like a vegetarian “beef like” portobello stew. I LOVED IT!!!!
    Only 4stars for now for its stew like form. I will attempt this soon with my instapot.

  37. Extremely bland and runny in the slow cooker. Followed the recipe to a T (I shouldn’t have). All the good reviews changed portions, cooking times and added new ingredients. Won’t be making this again and I’d say to avoid unless you want a bland veggie stew.

  38. Ok I read the comments and thought the liquidity was just from the instapot. It’s not, it’s from the liquid the mushrooms produce. This will be soup, not stew. I tried all of the tricks the author suggests to make a roux and thicken it up. Just know that this recipe gives a false hope of consistency via pictures. And I wish I could say the flavor was there but it wasn’t. Double up on everything and prepare to need extra acid on top of the wine.

  39. Very bland. Would not make again.

  40. WAYYYY too much liquid! When do you add the salt and pepper – not in directions? Very bland. Sorry, won’t be making this again.

  41. I cut the recipe in half and forgot to add the wine and the last step. Turned out beautifully in my new tiny 2 quart pressure cooker 😊

  42. This recipe was very good, but I would suggest changing the serving size. This would feed perhaps 3-4, but definitely not 6-8.

  43. I added 4 tbsp cornstarch and turned my instant pot to sauté. When using cornstarch liquid needs to be simmering to slow boil for it to thicken. I also added a 1/2 tsp kitchen bouquet for a darker gravy. All in all, recipe is very good, serving over corn grits.

  44. Can the wine be skipped on this recipe?