Barbecue Portobello Mushroom Burgers with Grilled Onions and Pineapple

Remember that easy and delicious barbecue sauce that we made together last week? Yes? Well, let’s do something with it other than just licking it straight off the spoon. Not that I know anybody who would do anything like that…

Please avert your eyes while I wipe barbecue sauce off my face.

So grilling. If you’re a carnivore, just the thought of grilling is probably enough to make you salivate. But if you’re a vegetarian, then you might be less than thrilled by the whole concept. Because often vegetarians get the short end of the stick during grilling season. Summer can be a endless loop of frozen veggie patties and tofu dogs. No bueno.

In an attempt to correct this problem, I set out to create a juicy, flavorful “burger” that the vegetarians could really sink their teeth into. And I think I finally hit the nail on the head with these Barbecue Portobello Mushroom Burgers with Grilled Onions and Pineapple.

As a self proclaimed carnivore, I have to admit that I COULD NOT STOP eating these portobello mushroom burgers. They are so ridiculously good! They have a lot of the same elements that you might find on a traditional burger, so that kind of tricks your brain into thinking you’re eating beef. Not that I think we need to be tricking ourselves (or others) into consuming vegetables. I just don’t know how else to explain it. Hopefully, you guys know what I’m getting at.

I’m confident in saying that even the meat-eaters will be able to get excited about these babies. And the vegetarians in your life with thank you for not forcing them to eat pre-formed, freezer-burned knock-offs. Happy grilling times for everyone!



Barbecue Portobello Mushroom Burgers with Grilled Onions and Pineapple

Serves 4

Barbecue Portobello Mushroom Burgers with Grilled Onions and Pineapple


  • 4 portobello mushrooms
  • 1 medium onion, sliced into rings
  • 4 pineapple slices
  • Extra-virgin olive oil
  • Salt
  • Black pepper
  • About 1/2 cup barbecue sauce
  • 4 brioche buns
  • 8 ounces havarti cheese, sliced
  • About 1 cup greens (arugula or spinach)


  1. Pre-heat your grill to medium-high.
  2. Remove and discard the stems from the mushrooms. Using a small spoon, scrape out and discard the gills. Gently wipe the mushroom caps with a damp paper towel to clean them.
  3. Brush both sides of the mushrooms and the onion rings with olive oil. Season with salt and pepper. Place the mushroom caps, cap side down, and the onion rings on your pre-heated grill. Close the lid and cook for 5 minutes.
  4. Then flip the mushroom caps and the onion rings. Brush the mushroom caps with barbecue sauce. Add the pineapple slices to the grill. Close the lid and cook for 2-3 minutes.
  5. Brush the mushroom caps with additional barbecue sauce. Flip the pineapple slices. Add the brioche buns to the cooler side of your grill, dividing the havarti cheese slices evenly over the bottom half of each of the buns. Close the lid and cook for an additional 2-3 minutes.
  6. Remove everything from the grill. Place the barbecue mushroom caps on top of the cheese on the bottom half of the buns. Then top with the grilled onions, pineapple slices and a handful of greens. Top each burger with the top half of the bun. Serve immediately.

45 comments on “Barbecue Portobello Mushroom Burgers with Grilled Onions and Pineapple”

  1. Wow now this is a burger! I love that you used your homemade barbecue sauce! And mushrooms and pineapple are my favorite toppings. Love this!

  2. One time in high school my friend asked me if portobello was meat. I never let her live it down.

  3. Ok so I used to HATE mushrooms, but since discovering the magic that portobellos are, I kinda love them! Homemade BBQ sauce and these burgers? SWOON.

  4. Portobello with pineapple (and your homemade BBQ sauce!) sounds absolutely delicious! Can’t wait to try this.

  5. Well this just looks AMAZING! I actually really like portabella mushroom burgers. You don’t even miss the meat!

  6. I too am a carnivore at heart, but this portobello burger would totally satisfy me! I love how juicy and saucy it looks, plus the toppings are perfect!

  7. Oh man, you know how to make one MEATY looking vegetarian burger. These look fabulous!

  8. This is a vegetarian burger that I can sink my teeth into! I’m loving the addition of pineapple. Yum!!

  9. In the words of Meg Ryan in When Harry Met Sally, YES YES YES! I’ll have what she’s having…

  10. I just love a good portobello burger!! This one sounds delicious!

  11. I love meat but sometimes I like to try something different and these portobello burgers are perfect. Pineapple is one of my favorite things to add while grilling so I love that you added my favorite flavors. Excuse me, while I wipe the barbecue sauce off of my face too!

  12. Just like you, I’m all about a meaty burg, but I LOVE portabello burgers just the same! That apricot Q sauce sounds perfect for these tasty veggie burgers! That melted cheese? It’s keeeeeelling me!

  13. This is the best vegetarian burger I have seen in a while, and the pineapple addition is top notch!

  14. Also being a self-proclaimed carnivore, I too drooled over these bad boys! I mean I already loved mushrooms, so the fact that you made them into a burger and topped them with BBQ sauce is basically equivalent to you sending me a love letter….so thanks 🙂

  15. I love portobello burgers and bet yours is just delicious with that barbecue sauce. The melted havarti and pineapple are such perfect toppings, too. What a wonderful dish to welcome summertime!

  16. This burger looks amazing!!!

  17. Goddamn!!! You are evil! Really evil because I want this burger now. Pineapples? Such a great great addition!

  18. That BBQ sauce, Liz!! On this burger is so mouthwatering, so delicious! It is genius! I don’t own a grill, but I do have a grill pan that will suit these veggies just fine! Thank you for this, Liz! Love it!

    • Oh yeah, it will work out just fine in a grill pan. Or even the oven too. I love cooking mushrooms that way as well!

  19. Mmmm! Love portobello mushrooms so I’m sure they taste amazing with barbecue! Thanks for sharing 🙂

  20. Ooooh grilled portobellos are the best. In fact, I love ALL grilled veggies! I think even more than grilled meat! These burgers looks awesome… I love that you used havarti!!

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  22. Ok so A) I’m in the process of perfecting a veggie burger recipe and so appreciate the inspo; and B) you SO NAILED ME as that BBQ-illiterate veg-centric summer person. Cannot wait to give these a whirl!

    • GIRL! You’re going to love this! Veggie patties can be hard to perfect. So that’s why I love the simplicity of a grilled portobello mushroom cap!

  23. I appreciate that there wasn’t a novel attached to this recipe! Have you tried marinating the mushrooms first? Sounds delicious!

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