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5 from 2 votes

Grilled Portobello Mushroom Burgers

These Grilled Portobello Mushroom Burgers are marinated in a pollo a la brasa-like marinade. They’re layered with lettuce, tomato, aji verde and red onion on a delicious St Pierre Brioche Burger Bun. They are my favorite vegetarian-friendly grilled burger! 
Prep Time15 mins
Cook Time10 mins
Total Time25 mins
Course: Dinner
Cuisine: American
Keyword: brioche bun, grilled mushroom burgers, portobello mushroom
Servings: 4
Calories: 123kcal
Cost: $12


Mushroom Marinade:

  • 2/3 cup soy sauce
  • 1- inch knob of ginger
  • 3 garlic cloves peeled
  • 1 tablespoon red wine vinegar
  • 1 aji amarillo or jalapeño
  • 1 teaspoon ground paprika

Mushroom Burgers:


How to Make the Mushroom Marinade:

  • In a blender, add the soy sauce, ginger, garlic, red wine vinegar, pepper of choice and paprika. Blend until very smooth, about 30 seconds.

To Marinate and Cook the Burgers:

  • Fire up and heat your grill over medium to high heat. Brush the grates with neutral oil (such as avocado oil).
  • Add the portobellos to a shallow baking dish and pour the marinade over the portobellos. Allow them to marinate for 5 minutes. This may not sound long enough but you don’t want them to get soggy.
  • Add the brioche buns to the grill, cut side down, and toast them until lightly golden brown, about 2 minutes. Add the portobellos to the grill and cook for about 5 minutes. Top them with slices of Swiss cheese and close the lid to the grill, about 1 minute, just until the cheese is melted. Remove the portobello mushrooms.

To Assemble:

  • Smother each bun with the aji verde (if using), add the lettuce, tomato, grilled portobello and red onion. Repeat with all of the burgers. Serve with potato salad or kettle chips for maximum summer experience.


Tips and Tricks:
  • You’re welcome to make the marinade up to 3 days ahead. You can store it in the fridge in an airtight container. Just be sure to give it a mix before using. 
  • Swiss cheese, I find works wonders with mushrooms, but feel free to use another cheese of choice. I think any melty cheese would be great. Medium sharp cheddar, mozzarella, pepper jack or fontina. 
  • I paired this recipe with my Aji Verde sauce which is always served with Pollo a la Brasa. Obviously that’s very optional. You can use other aiolis or a plain mayonnaise too! 
  • You can keep the St Pierre Brioche Burger Buns warm in a 200 degree F oven after you toast them if you’re moving a bit slow or starting and stopping the recipe


Serving: 4g | Calories: 123kcal | Carbohydrates: 10g | Protein: 11g | Fat: 5g | Saturated Fat: 3g | Cholesterol: 16mg | Sodium: 2203mg | Potassium: 514mg | Fiber: 2g | Sugar: 4g | Vitamin A: 644IU | Vitamin C: 6mg | Calcium: 155mg | Iron: 1mg