This oven-baked Portobello Mushroom Burger is loaded with healthy veggies and full of bold umami flavor! It’s perfect for busy weeknight dinners and vegan-adaptable.

portobello mushroom burger on plate with a brioche bun, chipotle mayo sauce, arugula, avocado, tomato, and cheese.

For years, this portobello mushroom burger was on the menu at our former restaurant—and I never ever tired of it! I still crave this vegetarian burger, and luckily, Brian loves it too, so we go through spells where we’ll just have it several days in a row. Do you do that too? I like how easy it is to make, perfect for busy nights- and how adaptable it is- easily made vegan. Yes, you can grill the portobello mushrooms, but for ease, I often just bake them in the oven or use the air-fryer. We also have this Spicy Miso Portobello Mushroom Burger, for something a little different.

Why You’ll Love This

  1. 30-minute meal! Quick and easy, perfect for busy weeknights.
  2. Vegan adaptable. Use vegan cheese (optional), vegan mayo, and whole wheat buns.
  3. Various cooking methods. Grill, roast in the oven, or use an air fryer.
  4. Healthy! Portobellos are rich in antioxidants and immune-boosting nutrients.

Portobello Mushroom Burger Ingredients

portobello burger fixings on plate - mushrooms, onions, cheese, tomato, avocado, arugula.
  • Portobello mushrooms: Use extra large mushrooms with the stems removed.
  • Red onions: Make quick pickled red onions or roast sliced onions with the mushrooms.
  • Cheese (optional): Use provolone, cambozola, sharp cheddar, smoked mozzarella, or vegan cheese. At the restaurant we used cambozola (super tasty!), but I’ve also been loving provolone. Both add good umami flavor and rich, melty texture.
  • Avocado, tomato, and greens: Add sliced avocado and tomato and a handful of arugula or other greens or microgreens.
  • Buns: Brioche buns are perfectly sweet and buttery! Or simply use whole wheat buns—also delicious.
  • Chipotle Mayo: Use the recipe or simply whisk together mayo (or vegan mayo), red wine vinegar (or apple cider), smoked paprika, chipotle powder (or chili powder), and a pinch of salt.

How to Make Portobello Mushroom Burgers

See notes for how to make grilled portobello mushrooms and how to use the air fryer!

Preheat oven to 400F.

Step 1: Prep the mushrooms. Brush the mushrooms clean with a brush or dry sponge and remove stems. Do not wash the mushrooms with water. Brush them with olive oil (or use a spray). Season generously with salt and pepper on both sides. Place on a sheet pan, gill-side down.

two portobello mushrooms gill-side down on baking sheet, seasoned with oil, salt, and pepper.

Step 2: Cook the mushrooms. Bake 10 minutes, adding a few extra minutes if the mushrooms are large. (Add sliced onions to the pan if you prefer them roasted instead of pickled.)

portobello mushrooms gill-side up on baking sheet, seasoned with oil, salt, and pepper.

Flip them and cook 5-7 more minutes, adding cheese to the gill side (if using) for the last few minutes until the cheese melts.

two portobello mushrooms on baking sheet in oven - one with squares of cheese on top.

Step 3: Make onions and Chipotle Mayo. Prepare the pickled red onions if you did not roast them with the mushrooms. Then prep the Chipotle Mayo or whisk together the ingredients for the quick version below (mayonnaise, vinegar, smoked paprika, chipotle powder, and salt).

Step 4: Toast the buns. Use a toaster or gently toast them on a skillet with a touch of oil.

two toasted brioche buns with chipotle mayo spread over top.

Step 5: Assemble. Spread Chipotle Mayo on the top and bottom of the buns, then top with a mushroom.

plate with toasted brioche buns, one with chipotle mayo on top, and the other with roasted portobello and melted cheese.

Add sliced tomato (seasoned with salt and pepper), and avocado (also seasoned with salt and pepper).

assembling portobello mushroom burger with brioche bun, stacked with roasted portobello, melted cheese, sliced tomato and avocado.

Garnish with arugula (or another type of lettuce or microgreens) and pickled onions and enjoy right away!

portobello mushroom burger on plate on brioche bun, stacked with melted cheese, sliced tomato and avocado, arugula, and pickled onions.

Other Serving Ideas!

Once you’ve tried this Portobello Mushroom Burger with cheese, roasted or pickled onions, Chipotle Mayo, tomato, avocado, and arugula, here are some other toppings ideas!

If you like these ideas, be sure to try our Spicy Miso Portobello Mushroom Burger!

FAQs

Do I need to clean the portobello mushroom caps?

Yes, but do not use water to do this. Simply use a brush or dry sponge to gently brush the gills.

Do I need to soak the mushrooms in a marinade?

Nope! This recipe is simple and ideal for quick dinners. Season the mushrooms in olive oil, salt, and pepper and let the natural umami flavor from the portobellos do the work.

Can I freeze roasted portobello mushrooms?

Yes, cooked mushrooms can be frozen for up to 3 months. Thaw in the refrigerator before reheating.

Are portobello mushroom burgers healthy?

Portobello mushroom burgers are rich in antioxidants and nutrients that boost immunity. They are also a great source of vitamins, minerals, and fiber, making them a nutritious vegetarian burger alternative.

What should I serve these burgers with?

Grilled or roasted corn and potatoes make a delicious warm weather meal!

Storage

Leftover portobello mushrooms can be stored in an airtight container in the refrigerator for up to 4 days. To reheat, warm them in the toaster oven or microwave.

portobello mushroom burger on brioche bun with melted cheese, sliced tomato and avocado, arugula, and chipotle mayo sauce.

Enjoy this easy Portobello Mushroom Burger recipe and let us know what you think of it in the comments below!

More Burger Recipes You Might Enjoy

Print
clock clock iconcutlery cutlery iconflag flag iconfolder folder iconinstagram instagram iconpinterest pinterest iconfacebook facebook iconprint print iconsquares squares iconheart heart iconheart solid heart solid icon
This oven-baked Portobello Mushroom Burger is loaded with healthy veggies and full of bold umami flavor! It's perfect for busy weeknight dinners and vegan-adaptable.

Portobello Mushroom Burger

5 Stars 4 Stars 3 Stars 2 Stars 1 Star 5 from 4 reviews
  • Author: Sylvia Fountaine | Feasting at Home
  • Prep Time: 10
  • Cook Time: 20
  • Total Time: 30 minutes
  • Yield: 2 1x
  • Category: sandwiches, dinner recipe
  • Method: baked
  • Cuisine: American
  • Diet: Vegetarian

Description

This oven-baked Portobello Mushroom Burger is loaded with healthy veggies and full of bold umami flavor! It’s perfect for busy weeknight dinners and vegan-adaptable.


Ingredients

Scale
  • 2 extra large portobello mushrooms, stems removed
  • 12 teaspoons olive oil (or use spray olive oil)
  • salt and pepper to taste
  • 1 red onion (either make pickled red onions or roast sliced onions with the mushrooms)
  • Optional cheese: provolone, cambozola, sharp cheddar, smoked mozzarella, or vegan cheese
  • 1 avocado, sliced
  • 1 tomato, sliced
  • Handful arugula or other greens or microgreens
  • 2 brioche buns or whole wheat buns

Chipotle Mayo  (quick cheater version below)


Instructions

  1. Preheat oven to 400F
  2. Brush mushrooms clean (do not wet or wash) with a brush or dry sponge and carefully remove stems. Brush or spray with olive oil and generously season with salt and fresh black pepper on both sides. Place on a sheet pan, gill-side down.  Bake for 10 minutes (if they are extra large, add a few more minutes) then turn them over. Cook 5-7 minutes, and add cheese to the gill side if using, letting it melt for the final few minutes.
  3. Make the quick pickled onions and Chipotle Mayo– whisking everything in a small bowl.
  4. When ready to assemble- toast the buns. You can do this in a toaster, or on a skillet with a little olive oil.
  5. Assemble the burgers: Spread the buns (top and bottom) with the Chipotle Mayo, place the portobello mushroom on the buns, add sliced tomato (season with salt and pepper), add avocado, (season with salt and pepper), top arugula and pickled onions. Top with the top bun.
  6. Serve immediately!

Notes

Leftover roasted portobello mushrooms can be kept in an airtight container in the refrigerator for up to 4 days. Reheat in a toaster oven or microwave.

Make ahead: Chipotle mayo and pickled onions can both be prepped ahead.

Roasted onions: Instead of pickled onions, you can slice a red onion into thin rings, brush with olive oil  and season with salt and pepper and roast along side the mushrooms, tossing halfway through.

Grill or air fry: The portobello mushrooms can also be grilled over medium heat (or use a grill pan on the stovetop) until tender, or cooked in an air fryer: 390F for 5 minutes, flip, continue cooking 3-5 minutes depending on how big they are.

Cheese: At our restaurant, we used cambozola cheese (super tasty) but I’ve also been loving provolone! Both add good umami flavor.

Nutrition

  • Serving Size: One burger, no cheese with vegan mayo
  • Calories: 457
  • Sugar: 10.7 g
  • Sodium: 1482.4 mg
  • Fat: 26.8 g
  • Saturated Fat: 3.8 g
  • Carbohydrates: 47.4 g
  • Fiber: 14.6 g
  • Protein: 6 g
  • Cholesterol: 10.4 mg

Share this with the world!

Subscribe
to get recipes via email

Leave a comment

Your email address will not be published. Required fields are marked *

Recipe rating 5 Stars 4 Stars 3 Stars 2 Stars 1 Star

Comments

  1. Omg I love this burger! I used my leftover homemade hummus (your recipe) plus chipotle in adobo sauce in place of the mayo. I also used pickled radish since that’s what I had. I used your quick sourdough buns recipe for the bun. This is such a winner meal! So easy and juicy and flavorful! Thank you!






  2. We like ours on the grill,however cant wait to try your chipotle mayo! I like to remove the gills b/c of dirt and possible critters in there you don’t want to eat.TIA






    1. Thanks so much- yes feel free to remove the gills if you prefer. 🙂 And grilling is s great option!

  3. Delicious! Easy. We skipped the cheese, roasted the onions, and made the chipotle mayo with Veganaise. Served on toasted whole wheat bun with tomato, avocado and arugula. A home run.






    1. Sounds perfect Frances! Glad you enjoyed and love your vegan adaption!

    1. That should work fine, just keep an eye as the mushrooms may need more or less time to cook.

Our Latest Recipes