Grilled portobello mushrooms make the best vegetarian burgers. Learn our technique and get our tasty recipe here.
Portobello mushrooms make a wonderful option for a veggie burger patty. They are meaty and delicious and cook quickly on the grill. There’s no veggies to chop or patty to form, just a flavorful portobello with Brie cheese and a tasty pesto mayonnaise spread on a burger.
Scroll down to read more about how it all comes together or click here to jump straight down to the recipe.
What Are Portobello Mushrooms?
Portobello mushrooms, sometimes called portabellas, are a kind of large mushroom that has a rich, earthy, savory flavor. Note that mushrooms have a lot of meaty flavor but are definitely not meat. They are not a vegetable either, but rather an edible fungus. They are a large mushroom, often 5 or 6 inches across, which make them a great option to grill and use as a burger patty.
One of the great things about portobello mushrooms is their umami (meaty) taste, which makes mushroom burgers something that even meat-eaters can get behind.
How To Make Portobello Burgers
Unlike most vegetarian burger recipes this one does not require any chopping of vegetables or forming of patties which makes this recipe fast! Add the marinade, grill, eat. Yum yum yum.
Start by trimming the stems off of your mushrooms and wipe off any dirt with a damp paper towel. Then, mix together your marinade of olive oil, fresh lemon juice, minced garlic, salt, and pepper. Brush the mushrooms generously on both sides with this mixture and let sit for ten minutes.
Preheat your grill to medium heat and add the portobello mushroom, gill side up. Grill until they start to develop nice grill marks, about four minutes, and then turn 90° to create cross-hatched grill marks, and continue cooking for two minutes more.
Flip and repeat the process on the other side, then flip them back to gill side up and place your Brie cheese and allow the cheese to melt. Take off of the grill and assemble your portobello mushroom burgers.
I love these with a pesto mayo spread. In small bowl combine your mayonnaise and pesto. Spread a tablespoon of the condiment on each hamburger bun, and add your grilled mushroom. Top with your favorite burger toppings, such as lettuce and tomato. So delicious!
Note that the idea behind this recipe (the portobello mushroom, the Brie cheese, and the pesto mayo) are inspired by a mushroom burger that was served at the Falcon Lake Deli in Manitoba, Canada, the restaurant that was owned by our editor Christine’s parents for years and years.Print
- 4 portobello mushroom caps
- 1/4 cup olive oil
- 2 Tbsp. lemon juice
- 1 garlic clove, minced
- 1/4 tsp. salt
- 1/4 tsp. pepper
- 3 Tbsp. mayonnaise
- 1 Tbsp. pesto, store-bought or our delicious recipe
- 4 oz. Brie cheese
- 4 hamburger buns
- Trim stem off of portobello mushrooms and wipe dirt off of the mushrooms with a wet paper towel.
- In bowl, mix together olive oil, lemon juice, garlic, salt, and pepper. Place mushrooms on plate gill-side-down and brush lightly with olive oil mixture. Flip the mushroom and brush the gill side with remaining mixture. Let sit ten minutes.
- Preheat grill to medium heat. Add mushrooms gill side up and grill until nice grill marks are underneath, about four minutes. Turn the mushrooms 90° to create grill marks and cook two minutes longer. Flip and repeat. Flip mushrooms again and place 1 ounce of Brie on the mushroom and allow to melt. Take off grill and place on plate.
- In small bowl combine mayonnaise and pesto. Spread 1 tablespoon of mixture on each bun. Add mushroom to bun. Top with your favorite burger toppings.
Love this recipe? I’d appreciate it if you could scroll down and add a *5 star rating* to help others know they’ll love it as well!
This post originally appeared in July 2016 and was revised and republished April 2023.