Portobello Mushroom & Caramelized Onion Burgers

I have to be honest, I had never had a portobello mushroom burger until the day I made this. I’ve always been a big fan of veggie burgers – but more so those that are made with a mixture of rice, beans, and veggies. I never thought just a mushroom itself could really be substantial enough to stand in for a regular burger patty – wether it be veggie, chicken, turkey, or beef.

Was I ever wrong!!! This is DEFINITELY one of my new favorites!


Portobello mushrooms are a perfect burger stand in.

All you meat eaters out there who are doubting me right now… I DARE YOU to try this!

Now that I’ve made this, I’m actually almost convinced that’s what they are meant for really, to be a burger. :)

It’s interesting too, because when the mushroom is grilled then topped with a bunch of delicious ingredients and stuffed in a bun, it barely tastes like a mushroom at all! It just has this great meaty consistency and wonderful flavor!



Portobello mushrooms are a great source of nutrients including selenium and potassium, and they are definitely a healthy substitution in a burger as they are low in calories, have only about 1 gram of fat, 5 grams of protein, and 3 grams of fiber (in a 1 cup serving)!

I decided caramelized onions and goat cheese would be worth a try, and it worked out amazing! The sweetness of the onions and creaminess of the goat cheese (can you tell I’ve had a little thing for goat cheese lately??) create a delicious burger topping. Then I garnished the burger with some tomato, field greens, and Dijon mustard… some organic ketchup may have snuck its way on the burger too… shhh.


Talk about UNREAL. It was slight torture trying to get through taking these pictures without biting into this juicy, flavorful, stack of deliciousness.



Oh, here’s one more picture, just for good measure.


5.0 from 3 reviews
Portobello Mushroom & Caramelized Onion Burgers
Prep time
Cook time
Total time
Serves: 4
  • 4 portobello mushrooms, stems removed
  • 2 tbsp balsamic vinegar
  • 2 tbsp olive oil, divided
  • 1 cup sliced white onion
  • 2 oz soft goats cheese
  • 1 on-the-vine tomato, sliced
  • 2 cups field greens
  • 4 tsp Dijon mustard
  • 4 whole-wheat burger buns
  1. Preheat the grill.
  2. Take a large ziploc, and place mushrooms in the bag, add the balsamic vinegar and 1 tablespoon of olive oil, and seal bag. Shake the bag until the mushrooms are coated in the vinegar and oil. Let sit for a few minutes while preparing the other ingredients.
  3. Heat a non stick pan over med-high heat. Add oil, let heat for 30 seconds, add onions, lower heat to medium, and cook, stirring often, until onions are soft and browned.
  4. Remove mushrooms from ziploc and place on the heated grill, round side up. Let cook for 2-3 minutes.
  5. Meanwhile, slice tomato, and wash lettuce, and prepare other preferred garnishes.
  6. Turn mushrooms over so they are flat side up, top with goats cheese (1/2 oz each) and caramelized onions. Continue to cook for 3 more minutes. Remove from grill.
  7. Using whole wheat buns, assemble burgers.
  8. Enjoy!
Need a gluten-free option, or just don't want the bun? These would be great just as a "stack", no bun needed! :)


Nutritionist in the Kitch



  1. jenn says

    hi christal,
    can these mushrooms also be done on the stove in a pan or just on the grill?!
    i can’t wait to try this. looks so yummy :0)

    • Christal says

      You could do them in a pan for sure! I would do a covered pan though, or you could bake them in the oven as well – I would suggest 350 for about 8 mins!


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