These Grilled Portobello Mushrooms are a great vegetarian side dish or main to serve at a barbecue. The Portobello mushrooms are marinated in a simple sauce so they take on lots of flavour, grilled until slightly charred and tender and then served with a chunky walnut and arugula pesto. They are easy to make and Vegan, Keto, Whole30, Paleo and Grain and Gluten Free.

Grilled Portobello Mushrooms
With barbecue season just weeks away, I have been on the hunt for fun veggie dishes that can be made on the barbecue.

Grilled Portobello Mushrooms
I already have quite a few barbecued vegetable side dishes on the site, like these Grilled Scallions & Asparagus and this Eggplant, but unfortunately the options for a vegetarian main dish is quite limited.

Grilled Portobello Mushrooms
Enter these Grilled Portobello Mushrooms which would satisfy even the hungriest carnivore. If you are looking for a filling “meaty” vegetable to serve a crowd, these mushrooms are perfect.

Grilled Portobello Mushrooms | Every Last Bite
These aren’t just grilled mushrooms, they are marinated grilled mushrooms and let me tell you, the marinade takes them to a whole new level of deliciousness. It’s a similar marinade to something I would use for steak, which only increases the “meatiness” of the mushrooms. They absorb a lot of the marinade so every bite is incredibly flavourful.

Grilled Portobello Mushrooms
The mushrooms are then topped with a simple arugula and walnut pesto. I really like the earthiness flavour that the walnuts add to the pesto which goes really well with the mushrooms. If you are preparing this for a barbecue, the pesto could be made a few days in advance to cut down on prep time.

Grilled Portobello Mushrooms
Leftover grilled Portobello mushrooms are just as good the next day. I had a container of leftovers in my fridge that I ate cold straight from the fridge and added into salads. They are incredibly versatile and would be great for breakfast with eggs, or even added into a wrap for lunch so definitely make extra, because you are going to want to have leftovers.

Grilled Portobello Mushrooms

Here are a few other grilled vegetable recipes that you might enjoy…

If you make this recipe let me know in the comment section below, I would love to hear what you think or take a photo and tag me (@everylastbite_) on Instagram, I love seeing your photos!

Grilled Portobello Mushrooms with Walnut Arugula

Every Last Bite
These Grilled Portobello Mushrooms are a great vegetarian dish to serve as a side dish or main at a summer BBQ.
5 from 7 votes
Prep Time 10 minutes
Cook Time 10 minutes
Total Time 20 minutes
Diets Dairy Free, Gluten Free, Grain Free, Paleo, Refined Sugar Free, Specific Carbohydrate Diet Legal, Vegan, Whole30
Servings 4 people
Calories 697 kcal


Marinated Portobello Mushrooms

  • 1 tbsp dijon mustard
  • 1/4 cup coconut aminos (or tamari/soy sauce)
  • 1/3 cup balsamic vinegar
  • 4 cloves garlic crushed
  • 1/2 tbsp dried oregano
  • 1/2 tsp chili flakes
  • 1/2 tsp pepper
  • 1/4 tsp salt
  • 2/3 cup extra virgin olive oil
  • 6-8 large portobello mushrooms

Walnut Arugula Pesto

  • 2 cups arugula
  • 1/3 cup toasted walnuts
  • 1/2 cup olive oil
  • 1/4 tsp salt
  • 1/2 tbsp lemon juice
  • 2 cloves garlic


  • Clean the portobello mushrooms by gently rubbing the cap and gills with a damp paper towel. Place the mushrooms cap side down in a large dish or alternatively a zip loc bag. In a bowl whisk together all of the ingredients for the marinade and once well combined, pour over the mushrooms. Leave them to marinate for approx 1 hour (up to 6 hours)
  • To make the pesto, in a blender or food processor combine all of the pesto ingredients and pulse until its blended into a smooth consistency. Taste and adjust seasoning accordingly and then place in the fridge until ready to serve. 
  • Heat a grill pan or barbecue on medium heat (or a sandwich press would also work) and grill the portobello mushrooms for approximately 5 minutes per side until grill marks form and they become tender. Once grilled cut then into 1/2 inch thick slices, drizzle any of the leftover marinade over each mushroom and then serve with a spoonful of the pesto on top. 
Calories: 697kcalCarbohydrates: 16gProtein: 5gFat: 70gSaturated Fat: 9gTrans Fat: 1gSodium: 698mgPotassium: 604mgFiber: 3gSugar: 7gCalcium: 58mgIron: 2mg
Tried this recipe?Leave a comment below and let us know how it was!