Baked Portobello Mushroom Recipe (An Easy Vegetarian Dinner!)

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This Baked Portobello Mushroom recipe makes an impressive-looking vegetarian dinner, but it’s also incredibly easy to prepare. I think it would make an excellent main course for your vegan friends or family members at Thanksgiving, or any another holiday meal for that matter.

baked portobello mushrooms recipe


Portobello mushrooms have a meaty quality that makes them a great meat substitute without relying on processed soy alternatives. You can serve them as vegetarian “steaks” or “burgers” with your favorite sides, or even stuff them with your favorite filling (like Thanksgiving stuffing!) as a hearty main course.

marinated portobello mushroom recipe

Health Benefits of Portobello Mushrooms

Because portobello mushrooms are a type of fungi, they grow by absorbing nutrients from the soil and organic matter around them. This can make them very rich in nutrients, including phytochemicals like conjugated linoleic acid (CLA), which is rarely found in non-meat sources. CLA has been shown to block aromatase, a protein that necessary for producing estrogen in women, and therefore it may also help to slow or stop cancers that are hormone-dependent (like breast cancer). (source)

Mushrooms are also one of the best sources of L-ergothioneine, which may help to protect against chronic inflammatory diseases and red blood cell disorders. Mushrooms are also a surprising source of plant-based protein, containing about 20% protein by weight.

overhead view of portobello mushrooms before cooking and after

Portobello mushrooms are also low in calories, with one mushroom having around just 18 calories. That means you can really load up on the side dishes to round out your meal!

How to Roast or Bake Portobello Mushrooms

Portobello mushrooms have a fairly neutral flavor, so it’s a good idea to let them marinate in a sauce for 15 minutes before baking them. Be careful not to let them sit in a sauce for too long, or they might get a slimy texture that wouldn’t be as appealing.

I tend to toss them in the marinade right before I set my oven to preheat. When the oven has reached the proper temperature, usually my mushrooms have marinated long enough and I can just transfer them to the oven to bake!

sliced baked/ roasted portobello mushrooms

It’s almost eery how meat-like the oven roasted portobello mushrooms can look! They also have a texture that is similar to meat when you bake them for about 30 minutes. When it’s warm enough to cook outside, they’re great on a grill, too!

Can you eat Portobello Mushroom Stems?

I feel like one thing that keeps people from eating portobello mushrooms more often, is that they don’t know what you can and can’t eat on the mushroom. The stems are technically edible, but they often have an unappealing “woody” texture, so I recommend that you just pull them off with your hands (which is super easy to do) and discard them.

Some people also like to use a spoon to remove the darker “gills” of the mushroom, but I didn’t take the time to do that in this recipe and I thought it turned out just fine.

I hope you’ll enjoy this baked portobello mushroom recipe as a delicious meat alternative soon! It’s delicious served over mashed cauliflower with vegan gravy.

portobello mushrooms with mashed cauliflower and gravy

baked portobello mushrooms recipe as a vegetarian main course
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5 from 9 votes

Baked Portobello Mushrooms (An Easy Vegetarian Dinner!)

These Baked Portobello Mushrooms are marinated in an easy gluten-free sauce and are oven roasted in just 30 minutes. Perfect as a vegan or vegetarian Thanksgiving main course!
Course Main Course
Cuisine American
Keyword baked portobello mushroom
Prep Time 15 minutes
Cook Time 30 minutes
Total Time 45 minutes
Servings 3
Calories 36kcal


  • 3 portobello mushrooms (stems removed)
  • 3 tablespoons tamari (gluten-free soy sauce)
  • 1 tablespoon balsamic vinegar
  • 1 garlic clove , minced
  • 1 teaspoon fresh sage , minced
  • 1 teaspoon fresh thyme leaves


  • Use a towel to gently rub the portobello mushrooms to help remove any dirt, then arrange them in a glass baking side, with the stem-side facing up. 
  • In a small bowl, stir together the tamari, vinegar, garlic, sage, and thyme. Use a spoon to pour the mixture over the 3 mushrooms, then use your hands to rub the sauce on the outside of the mushrooms, too. (Alternatively, you could put the mushrooms in a sealed container and gently shake them to coat them in the marinade, too.) 
  • Let the mushrooms marinate for 15 minutes, while your oven preheats to 400ºF. 
  • Bake the marinated mushrooms for 15 minutes, then use a spatula to flip them over and bake for an additional 15 minutes. It doesn't matter which side you bake first, but I think they look prettier for serving when you start with the stem-side up, then flip them over so the mushroom cap is nice and golden. 
  • Serve warm with your favorite side dishes and an extra sprinkling of fresh sage or thyme for presentation. Leftover mushrooms can be stored in an airtight container in the fridge for up to 3 days. 



Calories: 36kcal | Carbohydrates: 5g | Protein: 3g | Sodium: 1014mg | Potassium: 343mg | Fiber: 1g | Sugar: 3g | Vitamin A: 30IU | Vitamin C: 1.4mg | Calcium: 4mg | Iron: 0.8mg
Per Serving: Calories: 36,Carbohydrates: 5, Protein: 3, Fiber: 1, Fat: 0

Recipe Notes:

If you can’t tolerate soy, try using coconut aminos as a soy-free substitute for the tamari. If you don’t have issues with gluten, you can also use regular soy sauce instead of the tamari.

I used fresh sage and thyme to give this recipe more of a Thanksgiving flavor, but feel free to use any fresh herbs or seasonings you like. If you need to use dried herbs, I’d start with just an1/4 teaspoon of each and then add more to taste, if needed.

As always, if you try something different with this recipe please leave a comment below so we can all benefit from you experience.

Reader Feedback: What’s your favorite vegetarian or vegan main course? Do you serve any vegetarian options at your Thanksgiving feast? 

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talking about timing – i went grocery shopping with my mother a couple of days ago and bought some mushrooms to cook some tempeh scallops for a dinner with friends. i saw thesed portobello mushrooms and asked my mother what use could i make of them. she said they’re not really tasty and only good for drying and grating, so I didn’t buy them. I think I’ll be back to get some and try this recipe – thank you!

Nica zajac

I just made this tonight over a bed of mashed cauliflower/potatoes with your vegan gravy. Wow. This felt like such comfort food, you knocked it out of the park! Thank you, I’m so happy your website was recommended to me!

Lisa Huff

Oh wow, this looks so good!


My boyfriend is gluten free and tamari sauce is safe. It’s the soy sauce that has gluten. Might want to revise. Great recipe though


We are making ours tonight with some green chili chorizo and a hatch Chile shredded cheese on top that we are going to sprinkle over the top the last couple mins of cooking. Very excited!!


Very easy to make and delicious. Mushrooms were moist and tasty. Will definitely make again.

Pamela L Litchford

I tried this recipe for the first time two weeks ago; loved it.

Bought more portobello mushroom caps to make again!


Marinated mushrooms?! Wow I made these mushrooms tonight but ate them w brown rice and roasted green beans in lettuce wrap. My entire family loved this!

LiN Joy

Love this for veggie yet low carb and can vary it so much with different veggies, garnishes; varying prep steps; marinated or not; diverse spice choices, including using a blend of colorful roasted veggies for holiday… a true kitchen sink recipe to use up whatever bits are in the fridge!!

Andrea T.

Tried this recipe this evening even though I only had dried herbs. I omitted the oil. The mushrooms never made it to the dinner table. Fantastic savory marinade. Thank you. This recipe will be a “frequent flyer” in our household.


Why does this recipe have so much sodium? I have to watch my sodium very carefully. Any suggestions?

    Megan Gilmore

    Tamari is high in sodium, but you can use reduced sodium if you need to!


Just made this, but instead of using sage and thyme, I used dried tarragon and it was delicious. I will definitely be making it again soon!

Sherri Bailey

Used the basics but since we were having Mexican food I totally changed the marinade. Marinated the mushrooms with a combination of lime juice,a can of green chilies, 2 cloves garlic minced, thinly sliced green onions, 1/4 teaspoon cumin, chopped fresh cilantro & a little hot sauce. Topped the Tacos with sour cream & guacamole, came out wonderfully.


I made this recipe two nights ago. Wow! So easy and so delicious. I had planned to serve it with pesto, but ended up using the pesto for something else because these mushrooms tasted perfect without the extra sauce. I only had two mushrooms instead of three, so I hovered over the servings amount, as you showed us on Instagrams, and changed it to two. Thanks for the tip and for this wonderful recipe.

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