Portobello Mushroom Burger with Mozzarella, Roasted Peppers and Pesto Mayo Recipe

If you’re craving a seriously satisfying burger but want to keep things fresh, vibrant, and meat-free, this Portobello Mushroom Burger with Mozzarella, Roasted Peppers and Pesto Mayo is about to become your new go-to. Juicy marinated mushrooms, creamy mozzarella, smoky roasted peppers, and a zesty pesto mayo—every bite bursts with Mediterranean flair and crave-worthy flavor!

this …

Ingredients You’ll Need

This burger is all about letting a handful of high-impact ingredients shine. Each one brings its own punch of taste, texture, or color—making every bite of your Portobello Mushroom Burger with Mozzarella, Roasted Peppers and Pesto Mayo a total delight.

• Portobello mushroom caps: Their beefy texture and ability to soak up marinade make them the perfect plant-based burger “patty.”
• Balsamic vinegar: Adds tangy depth and helps tenderize the mushrooms.
• Low sodium soy sauce: Boosts umami without overwhelming saltiness.
• Olive oil: Helps deliver flavor and keeps everything juicy as it grills.
• Montreal steak seasoning: A punchy, peppery, garlicky blend for bold, savory flavor.
• Fresh mozzarella: Melts lusciously—its creamy flavor balances the tang and smokiness.
• Roasted red peppers: These add sweet, smoky, and slightly tangy notes. Jarred or homemade both work well!
• Red onion: Grilled slices provide little pops of caramelized flavor and irresistible crunch.
• Pesto: Homemade or jarred, pesto brings that unmistakable basil-garlic richness to your mayo.
• Light mayonnaise: The base for our pesto mayo, lending silkiness with a lighter touch.
• Whole wheat buns: A nutty, fiber-rich base to hold all your delicious fillings in place.

Variations

One of the best things about the Portobello Mushroom Burger with Mozzarella, Roasted Peppers and Pesto Mayo is how easily you can riff on it. Whether you’re following a specific diet, feeding kiddos, or just using what’s already in your fridge, there’s tons of room to make this burger your own.

• Make it vegan: Use your favorite plant-based mozzarella and swap in vegan mayo—your burger will still be just as delicious and creamy.
• Try a different cheese: Provolone, feta, or even goat cheese add a unique twist and melt beautifully over the mushrooms.
• Stuff the mushrooms: Before grilling, tuck a little sautéed spinach, sun-dried tomatoes, or other veggies inside the mushroom caps for bonus flavor and texture.
• Switch up the buns: Use sourdough, ciabatta, or even pretzel rolls to match your mood or what’s available at your bakery.

How to Make Portobello Mushroom Burger with Mozzarella, Roasted Peppers and Pesto Mayo

Step 1: Whip Up the Pesto Mayo

Start by stirring together the pesto and light mayo in a small bowl until well combined. You want it creamy, herby, and impossibly scoopable—the perfect spread for your toasted buns later. Give it a taste and adjust the pesto level to get your balance just right.

Step 2: Marinate the Mushrooms

In a large bowl, whisk together the balsamic vinegar, soy sauce, olive oil, and Montreal steak seasoning. Drop in the cleaned portobello caps and use a spoon to make sure each one is coated all over. Let them marinate at room temperature for 20–30 minutes, turning occasionally so they soak up all that goodness.

Step 3: Fire Up the Grill

Preheat your outdoor grill or indoor grill pan to medium heat. Brush the grates with oil or lightly mist the pan so nothing sticks. Place the marinated mushrooms on the grill, saving the marinade for basting. Grill the mushrooms 5–7 minutes per side, brushing with extra marinade as they cook and watching as they turn juicy and tender.

Step 4: Cheese, Onions, Peppers and Buns

In the last minute of grilling, top each portobello with mozzarella slices so they gently melt into all those savory nooks. While that’s happening, grill the red onion slices for about a minute per side and toast the buns until lightly crisped—these steps add layers of sweet, smoky, and warm textures that make the burger truly special.

Step 5: Assemble and Enjoy

Spread a generous dollop of your pesto mayo on each bun. Layer on the melty mushroom, then pile on the grilled onions and roasted red peppers. Close up your masterpiece and get ready for a Portobello Mushroom Burger with Mozzarella, Roasted Peppers and Pesto Mayo experience you’ll want to savor again and again!

How to Serve Portobello Mushroom Burger with Mozzarella, Roasted Peppers and Pesto Mayo

Garnishes

Fresh basil leaves, a sprinkle of extra steak seasoning, or even a little swirl of extra pesto across the top will really make your Portobello Mushroom Burger with Mozzarella, Roasted Peppers and Pesto Mayo pop—both visually and flavor-wise. For an extra-crunchy finish, add a few arugula leaves or pickled red onions right before serving.

Side Dishes

You can’t go wrong with some crispy sweet potato fries, a simple Caesar salad, or a bright tomato-cucumber salad on the side. For casual backyard vibes, classic kettle chips or grilled corn make this meal complete.

Creative Ways to Present

Try serving these burgers open-faced, stacked high with extra roasted veggies, or sliced and layered over a big bed of greens for a hearty salad. Skewer mini versions on slider buns for a cute party platter—trust me, these disappear fast at gatherings!

Make Ahead and Storage

Storing Leftovers

If you have leftover mushrooms or assembled burgers, store them in an airtight container in the fridge for up to 3 days. It’s best to keep the buns separate and assemble just before serving so everything stays fresh and tasty.

Freezing

The marinated (but uncooked) portobello caps freeze well—just pat them dry, wrap tightly, and pop in the freezer for up to a month. Avoid freezing assembled burgers, as the texture of the cheese and veggies can get a little wonky once thawed.

Reheating

Reheat burger patties in a skillet over medium heat or on the grill for a few minutes per side until warmed through. If reheating assembled burgers, tent them loosely with foil and use a hot oven for 8–10 minutes to keep the bread from drying out.

FAQs

Final Thoughts

If you love bold flavors, tender textures, and a burger you can truly feel good about eating, you have to give the Portobello Mushroom Burger with Mozzarella, Roasted Peppers and Pesto Mayo a try. It’s vibrant, filling, and oh-so-satisfying—just the kind of recipe that brightens up any mealtime. Let me know how you make it your own, and happy grilling!

Print