Introduction
Grilled Portobello Mushroom Burgers with Pesto Mayo are the ultimate vegetarian twist on a classic burger. These meaty, juicy mushrooms are marinated and grilled to perfection, delivering a rich, smoky flavor that rivals any traditional beef burger. The addition of creamy, herbaceous pesto mayo elevates every bite, adding freshness and a touch of indulgence. Topped with crisp lettuce, ripe tomatoes, and optional cheese, these burgers are not only satisfying but also visually stunning. Perfect for a casual weeknight dinner, a weekend BBQ, or even a special gathering, this recipe proves that vegetarian food can be both wholesome and gourmet.
Why I Love This Recipe
I love this recipe because it transforms a simple mushroom into a flavorful, gourmet experience. The Portobello caps have a meaty texture that grills beautifully, giving each bite a satisfying juiciness that even meat-lovers will crave. The marinade of olive oil, balsamic vinegar, and garlic infuses the mushrooms with a rich depth of flavor, while the smoky grill adds an irresistible char.
What makes this burger truly special is the pesto mayo—it’s creamy, herby, and slightly tangy, perfectly complementing the earthy mushrooms. The combination of textures—from the tender mushroom to the crisp lettuce, juicy tomatoes, and soft toasted bun—creates a harmonious bite that is both indulgent and fresh.
Why It’s a Must-Try Dish
This dish is a must-try because it redefines what a burger can be. The Grilled Portobello Mushroom serves as the perfect vegetarian alternative to meat, offering a satisfying, meaty texture while remaining light and wholesome. Each mushroom cap absorbs the flavors of the marinade, creating layers of taste that are both savory and slightly tangy, complemented by the smoky notes from the grill.
The pesto mayo is the magic touch—it adds a burst of freshness and richness that elevates the entire burger. When combined with crisp lettuce, juicy tomatoes, and toasted buns, each bite is an explosion of textures and flavors that feels indulgent yet healthy.
Recipe Info
- Preparation Time: 15 minutes
- Cooking Time: 10 minutes
- Total Time: 25 minutes
- Servings: 4 burgers
- Calories: Approx. 350 kcal per burger
- Cuisine: American / Vegetarian
- Course: Main Course / Lunch / Dinner
Ingredients
For the Burgers:
- 4 large Portobello mushroom caps, stems removed
- 2 tbsp olive oil
- 1 tbsp balsamic vinegar
- 1 tsp garlic powder
- Salt and pepper, to taste
For the Pesto Mayo:
- 3 tbsp mayonnaise
- 2 tbsp basil pesto (store-bought or homemade)
- 1 tsp lemon juice
Toppings:
- Lettuce leaves
- Sliced tomatoes
- Sliced red onion
- Avocado slices (optional)
- Cheese slices (optional, like mozzarella or cheddar)
For Serving:
- 4 burger buns, lightly toasted
Simple Cooking Directions
- Marinate mushrooms in olive oil, balsamic vinegar, garlic powder, salt, and pepper for 10 minutes.
- Grill mushrooms over medium-high heat for 5–7 minutes per side.
- Mix mayonnaise, pesto, and lemon juice for the sauce.
- Assemble burgers with buns, pesto mayo, mushrooms, and toppings.
Step-by-Step Recipe Preparation Method
- Prepare the Mushrooms:
- Clean Portobello caps by gently wiping them with a damp paper towel. Remove the stems.
- Marinate:
- In a small bowl, mix olive oil, balsamic vinegar, garlic powder, salt, and pepper. Brush this mixture on both sides of the mushrooms. Let them sit for 10 minutes.
- Preheat Grill or Pan:
- Heat a grill or grill pan over medium-high heat. Lightly oil the grill grates.
- Grill Mushrooms:
- Place mushrooms on the grill, gill side up. Grill for 5–7 minutes per side, until tender and juicy.
- Make Pesto Mayo:
- In a small bowl, combine mayonnaise, basil pesto, and lemon juice. Stir until smooth and creamy.
- Toast Buns:
- Lightly toast burger buns on the grill for 1–2 minutes until golden.
- Assemble Burgers:
- Spread pesto mayo on both sides of the buns. Place grilled mushrooms on the bottom bun. Layer with lettuce, tomato, onion, avocado, and cheese if desired. Cover with the top bun.
How to Serve
Serve immediately with a side of sweet potato fries, garden salad, or classic potato chips. Garnish with extra pesto mayo or fresh basil leaves for added flavor.
Additional Recipe Tips
- For extra smoky flavor, sprinkle mushrooms with smoked paprika before grilling.
- Marinate mushrooms for up to 30 minutes for deeper flavor.
- Use whole grain or brioche buns for a gourmet touch.
Variations
- Vegan Version: Use vegan mayonnaise and skip cheese or use plant-based cheese.
- Spicy Version: Add sriracha or chili flakes to the pesto mayo.
- Mediterranean Version: Top with roasted red peppers, feta cheese, and arugula.
Freezing and Storage
- Grilled mushrooms: Can be frozen for up to 1 month in an airtight container.
- Pesto mayo: Best kept in the refrigerator for up to 5 days.
- Assembled burgers: Best enjoyed fresh; avoid freezing once assembled to maintain texture.
Special Equipment Needed
- Grill or grill pan
- Basting brush
- Small mixing bowl for pesto mayo
Conclusion
Grilled Portobello Mushroom Burgers with Pesto Mayo are a delightful and satisfying plant-based meal that’s full of flavor and easy to prepare. They’re versatile, customizable, and perfect for both casual dinners and backyard barbecues. With juicy mushrooms, creamy pesto mayo, and fresh toppings, this recipe proves that vegetarian food can be just as indulgent and delicious as traditional burgers.

Grilled Portobello Mushroom Burgers with Pesto Mayo
Description
Grilled Portobello Mushroom Burgers with Pesto Mayo are a mouthwatering alternative to traditional beef burgers, packed with flavor, juiciness, and a hearty texture that even meat lovers will adore.
Ingredients
For the Burgers:
For the Pesto Mayo:
For Serving:
Instructions
-
Prepare the Mushrooms : Clean Portobello caps by gently wiping them with a damp paper towel. Remove the stems.
-
Marinate : In a small bowl, mix olive oil, balsamic vinegar, garlic powder, salt, and pepper. Brush this mixture on both sides of the mushrooms. Let them sit for 10 minutes.
-
Preheat Grill or Pan : Heat a grill or grill pan over medium-high heat. Lightly oil the grill grates.
-
Grill Mushrooms : Place mushrooms on the grill, gill side up. Grill for 5–7 minutes per side, until tender and juicy.
-
Make Pesto Mayo : In a small bowl, combine mayonnaise, basil pesto, and lemon juice. Stir until smooth and creamy.
-
Toast Buns : Lightly toast burger buns on the grill for 1–2 minutes until golden.
-
Assemble Burgers : Spread pesto mayo on both sides of the buns. Place grilled mushrooms on the bottom bun. Layer with lettuce, tomato, onion, avocado, and cheese if desired. Cover with the top bun.