Portobello mushroom caps provide a hearty, vegetarian alternative to beef patties in this portobello mushroom burger recipe. A slather of avocado chimichurri sauce is the perfect finishing touch that will have even the most vocal meat lovers gobbling up their veggies.
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“OMG this is a delicious burger and definitely a nice casual date night at home. We are not vegetarians but try to be 80% of the time. Will definitely have again.” -Sheryl, FoodieCrush reader
These Mushroom Burgers Deliver Big Savory Flavor
I love thinking outside the box with my burgers. Sometimes I’ll infuse them with bold garlic flavor, sometimes I’ll put a Korean spin on them, and sometimes I’ll swap out the hamburger for ground turkey.
This time, I ditched the meat entirely and replaced it with a juicy, savory, and — believe it or not — meaty portobello mushroom cap. This sizable mushroom variety is deliciously earthy, with a tooth-sinking denseness that tricks your mouth into thinking you’re eating a burger rather than a pile of veggies.
Instead of topping my portobello mushroom burger with mayo or mustard, I made a tangy chimichurri sauce, this time spiked with perfectly ripe avocado mixed in to give some serious flavor to this burger.
Whether you’ve got hungry vegetarians to feed or are experimenting with meat-free cooking, these hearty veggie burgers are always a good idea.
Enjoy!
Heidi’s Tips for Recipe Success
No outdoor grill? No problem! You can cook the portobello caps on a stovetop grill pan, or even in a cast-iron skillet if that’s what you’ve got, so you can make them no matter what time of year.
Lots of portobello burger recipes ask you to marinate the mushrooms before grilling, but I don’t think that’s necessary flavor-wise, and it can often make them soggy. A drizzle of olive oil and a healthy sprinkling of salt and pepper is all that’s needed to bring out the portobello’s meaty flavor.
What’s in This Recipe?
The full recipe, with amounts, can be found in the recipe card below.
- Portobello mushrooms — If they’re dirty, avoid rinsing them under running tap water which will water-log them. Instead, dampen a paper towel and gently rub off any dirt that’s clinging to the mushrooms.
- Veggies — I like to top my burgers with grilled onions and red bell peppers, plus wilted spinach. You can doctor up your burgers however you like.
- Olive oil — Helps the seasonings stick to the mushrooms.
- Seasonings — Kosher salt, black pepper, and dried oregano are my spices of choice here.
- Cheese — The earthy portobellos pair especially well with smoked mozzarella, but you can use any cheese you like.
- Hamburger buns — I’ve also served these on pita flatbreads before.
- Avocado chimichurri — Ripe avocado, fresh herbs, garlic, and a little lemon and vinegar are blitzed in a food processor to make the tangy chimichurri sauce.
How to Make Portobello Mushroom Burgers
- Prep the portobellos. Remove the stems and drizzle the caps with a glug of olive oil. Season with salt, pepper, and oregano.
- Grill over medium-high heat. The mushrooms will need about 10 minutes per side to soften. If you’re making yours a “cheeseburger,” add the sliced cheese near the very end of the cooking time.
- Cook the veggies. I sautéed the veggies on the stove, but if you were doing this on an outdoor grill, feel free to grill the onions and peppers right on up. Add the spinach to the hot vegetables after they’ve been pulled from the grill, give a good stir, and the heat should be enough to wilt and flavor the spinach just right.
- Make the avocado chimichurri. Just add everything to the bowl of a food processor and blend until smooth.
- Assemble. I like to toast the burger buns on the grill before loading them up with toppings; this prevents the buns from falling apart as the chimichurri sauce soaks into them.
If you make this recipe, please let me know! Leave a ⭐️⭐️⭐️⭐️⭐️ rating below, leave a comment to tell us what you think, and tag me on Instagram @foodiecrush.
Portobello Mushroom Burger Recipe
Ingredients
Portobello Burgers
- 2 large portobello mushrooms
- 1 red bell pepper, sliced into ¼ inch rings
- ½ red onion, peeled and sliced into ¼ inch rings
- 1 handful fresh spinach
- extra virgin olive oil
- 1 teaspoon dried oregano
- kosher salt and freshly ground black pepper
- smoked mozzarella cheese
- 2 pieces flatbread pitas or 2 soft burger buns
Avocado Chimichurri
- 1 avocado, peeled and pitted
- 3 cloves garlic, peeled
- ¼ cup olive oil
- ¼ cup flat leaf parsley leaves
- ¼ cup cilantro leaves
- juice of 1 lemon
- 1 teaspoon red wine vinegar
- 1 pinch red chili flakes
Instructions
- Prep the grill. Prepare an outdoor or indoor grill with cooking spray or a drizzle of olive oil and bring to medium high heat.
- Grill the mushrooms. Stem the clean portobello caps and drizzle both sides with olive oil. Season with kosher salt, freshly ground black pepper and sprinkle with the oregano. Place on the grill and cook on each side for 10 minutes or until the mushrooms soften and grill marks appear. Add cheese to the mushroom caps if desired and cook until cheese melts.
- Sauté the vegetable toppings. Meanwhile, add a drizzle of olive oil to the red bell pepper and red onion and season with kosher salt and freshly ground black pepper. Heat a large non stick skillet on medium heat and cook the red bell pepper and red onion stirring occasionally for 10-15 minutes or until softened and lightly browned. Transfer to a bowl and then add the spinach to the frying pan and cook for 1-2 minutes or until the spinach wilts. Turn off the heat and set aside.
- Make the creamy chimichurri. Spoon the avocado into a blender or food processor with the garlic, olive oil, parsley, cilantro, lemon juice red wine vinegar and chili flakes. Season with a pinch of kosher salt and freshly ground black pepper. Blend for 30 seconds to 1 minute.
- Heat up the buns and assemble the burgers. Warm the buns or flatbread on the grill or grill pan. Slather the avocado mixture on the bottom bun or piece of flatbread then layer with the mushroom cap, half of the spinach, red bell pepper and onions. Top with the bun and serve.
Nutrition
What to Serve With Portobello Burgers
- Rosemary Garlic Fries
- Mixed Grilled Vegetables
- Creamy Coleslaw
- Avocado Greek Salad
- Arugula Salad with Sun-Dried Tomatoes and Pine Nuts
- Baked Mac and Cheese
Storage Tips
Once grilled, the portobello burgers are best enjoyed right away. However, leftovers will last up to 3 days in the fridge. The avocado chimichurri will also last about 3 days, noting that it might oxidize over time.
More Hearty Vegetarian Dinner Recipes
- Caramelized Onion and Sweet Potato Pizza
- White Bean Stew
- Veggie Burrito Bowls
- Vegetable Ratatouille
- Homemade Falafel Sandwiches
- Vegetarian Chili
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Sheryl Schrager
OMG this is a delicious burger and definitely a nice casual date night at home. We are not vegetarians but try to be 80% of the time. Will definitely ha e again. Have made a few recipes with portobello burgers and my fav for sure.
Mandee
I made a version of these last night – YUM! https://www.facebook.com/cookinspiredchefapproved/photos/pcb.1457926470995861/1457926127662562/?type=3&theater
Ashley
I made a variation of this today. I used a marinate that for the mushroom….Balsamic vinegar, olive oil, pink salt, pepper, oregano, and basil (marinade 15 minutes each side)…I love your avocado dressing….it is so great. I definitely feel like I would use this for lettuce wraps.
Such a good idea to turn this into wraps. Thanks Ashley.
Cat
This was sooo good. The avocado chimichurri was delicious. Thank you for the inspiration.
I’m so glad you liked it Cat! Thank you for coming back and sharing.
Zenobia Fennell
I made the Portobello Mushroom Burger with Avocado Chimichurri this weekend. It was sooooo good! I will definitely keep this recipe on file!
Kristine @ Santanafoods
Burger with mushroom, looks amazingly delicious!
Millie | Add A Little
Yum!!
Shinee
Gosh, this burger looks great. I’m not even vegetarian, but I love mushrooms!
And I totally agree with less choices=less stress=more happiness! I’m very intrigued about Courtney’s Capsule Kitchen. Going to check it out…
I’m not veg either, and it is for sure a favorite.
Arthur in the Garden!
Yum
Sommer @ASpicyPerspective
I so see my mouth bursting with all those amazing flavors in this mushroom burger recipe! Delish!
JulieD
What a great idea…and these burgers look amazing! :) :)
Marloes
Oh mi, Oh my! Portobelloburgers als amazing. This one looks so good
Lori @ RecipeGirl
This is amazingly delicious!
bev @ bevcooks
Oooooooo these are so pretty. And I’m alllll about less is more. Except for cheese. More is more. Obv.
Mary
All of these recipes look fantastic. I’m craving that portobello burger like mad now. (And I love the idea of a capsule kitchen project too!)
Kelly
Thanks for sharing Courtney’s sites. I’m always looking for a way to simplify!
This burger looks so, so good. Pinning now!
Angela @ Eat Spin Run Repeat
First of all, this burger looks delicious! I love portobellos, even better than real-meat burgers! I’m also a fan of Courtney’s, and I think I first “met” her via Zen Habits. I love the idea of simplifying in all areas of life, and I totally get how fewer choices in the kitchen can help to reduce overwhelm, clutter, waste and decision fatigue. I’m a HUGE veggie lover, and like to think that the more variety, the better. That’s true from an overall diet perspective, but I’m starting to learn that it doesn’t have to happen at every meal! These days my meals are more simple, and I’m a creature of habit so it’s a-ok by me!
Laura (Tutti Dolci)
Portobello mushrooms are the best, I love this burger!
Katrina @ Warm Vanilla Sugar
These are so fancy-schmancy and delicious looking!! That sauce sounds like a dream!
Cecile@My Yellow Farmhouse
I am sooo all-over the recipe for the Portobella burger!! I’ve been trying to eat more healthy and this delicious recipe is going to be made very, very soon. Great post – great recipes, as always !!
Jen @ Baked by an Introvert
This portobello burger is the best thing I’ve seen all morning! Simply swooning.
Veronica
I love portobello burgers…and adding avocado is even better! Making this for lunch soon!
Sandy @ ReluctantEntertainer
Courtney is awesome! And so is the burger. WOW. I wish you’d fix it for me for lunch today. LOL Really fun idea, love this post, Heidi!
June Burns
Wow that looks great! I’ve never tried a portobello “burger” before but this variation would be delicious :)
Cara Tegler
What a fun idea!
I love the avocado that you added to your chimichurri, a lovely richness it would add. Mmm!