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

Get ready for your new favorite veggie burger: the Portobello Mushroom Burger with Mozzarella, Roasted Peppers and Pesto Mayo. Juicy portobello caps soak up a tangy marinade, pair up with creamy mozzarella and smoky roasted peppers, then get the ultimate flavor upgrade from herby pesto mayo. It’s hearty, cheesy, and absolutely bursting with colorful, Mediterranean-inspired flavor!

Ingredients You’ll Need

Every ingredient in this Portobello Mushroom Burger with Mozzarella, Roasted Peppers and Pesto Mayo serves a purpose, from building savory depth to bringing color and freshness. You’ll be amazed at how a handful of bold flavors, when layered together, create a burger that tastes and looks so special.

• Portobello Mushroom Caps: Choose large, firm caps for the perfect meaty texture and generous burger base.
• Balsamic Vinegar: Gives the mushrooms a robust tang and deepens their savory vibes.
• Low Sodium Soy Sauce: Adds savory umami and a hint of saltiness—much friendlier to your ticker than regular sodium versions.
• Olive Oil: Ensures a silky marinade and keeps mushrooms juicy on the grill.
• Montreal Steak Seasoning: This is what brings bold, peppery character and just a touch of smokiness.
• Fresh Mozzarella: Melts beautifully—if you can, get it pre-sliced to save some prep time.
• Roasted Red Pepper: Either jarred or homemade works; slice for easy layering and a sweet-smoky punch.
• Thick Slices Red Onion: They caramelize as they grill, adding mild sweetness and crunch.
• Pesto: Store-bought or homemade gives the mayo a burst of herbaceous flavor.
• Light Mayo: Lends creamy body to the pesto spread—feel free to use your favorite brand or even a vegan option.
• Whole Wheat Low Calorie Buns: The soft, hearty bun holds everything together without stealing the show; Martin’s is a great option!

Variations

This recipe is wonderfully adaptable, so go ahead—personalize your Portobello Mushroom Burger with Mozzarella, Roasted Peppers and Pesto Mayo to fit your cravings or what’s in your pantry. A few simple swaps or additions are all it takes to make it your own.

• Go Vegan: Swap the mozzarella for your favorite plant-based cheese and use vegan mayo—every delicious bite remains just as satisfying and rich.
• Make it Gluten-Free: Choose gluten-free buns or serve the burger “naked” over a salad for an extra-light option.
• Add Greens: Layer in baby spinach or arugula for a peppery crunch and a beautiful pop of green.
• Pepper Power: Try other roasted peppers—yellow, orange, or poblano bring new dimensions of flavor and color.

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

Step 1: Whip Up the Pesto Mayo

In a small bowl, stir together the pesto and light mayo until smooth and creamy. This simple step is pure joy—nothing transforms a burger quite like a flavorful spread you can make in seconds.

Step 2: Marinate the Mushrooms

Whisk the balsamic vinegar, soy sauce, olive oil, and Montreal seasoning together in a large bowl. Add your portobello caps and toss gently, making sure each one is well coated. Let them marinate for 20–30 minutes at room temperature, flipping once or twice so every bit gets to soak up all that savory, tangy flavor.

Step 3: Heat Up the Grill

Preheat your grill or grill pan to medium heat. Once hot, brush the grates lightly with oil or give your grill pan a quick spray, to make sure nothing sticks. Those mushrooms are about to get some gorgeous grill marks!

Step 4: Grill Mushrooms & Onions

Lay the marinated portobellos on your grill, reserving any leftover marinade for brushing. Grill them 5–7 minutes per side, basting occasionally, until they’re juicy, tender, and charred. During the final minute, top each cap with mozzarella so it gets nice and melty. While the mushrooms grill, pop the onions alongside—just a minute per side creates sweet, smoky layers of flavor.

Step 5: Toast & Build

Split your whole wheat buns and grill them cut-side down until warmed and toasty. Now comes the fun part: spread the pesto mayo on each bun, then pile on your cheesy mushroom, grilled onions, roasted red pepper strips, and anything else you like. Sandwich it all together and take a huge, glorious bite!

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

Garnishes

Add a sprinkle of chopped fresh basil or parsley for a vivid, herbaceous finish, or tuck a few crisp lettuce leaves under your mushroom for extra crunch and color. Sometimes a tiny drizzle of balsamic glaze over the finished burger is just the thing to make flavors pop—even more Italian-inspired flair!

Side Dishes

This burger pairs effortlessly with classic sweet potato fries or a crisp side salad. For something a little different, try it next to grilled corn, a Mediterranean chickpea salad, or even a pile of balsamic marinated cherry tomatoes. Everything fresh and vibrant works beautifully.

Creative Ways to Present

If you’re serving guests, cut the Portobello Mushroom Burger with Mozzarella, Roasted Peppers and Pesto Mayo in halves or quarters and spear with a cocktail pick—it makes a wonderful, hearty appetizer. Or, pile all the burger fixings into a wrap or lettuce cup for a fresh, picnic-ready twist. You can even serve “deconstructed,” with all the toppings arranged platter-style for a DIY burger bar!

Make Ahead and Storage

Storing Leftovers

If you have extra burgers or components, let the mushrooms and toppings cool, then store each separately in airtight containers in the fridge for up to 3 days. Avoid assembling the burgers until ready to enjoy—they’ll stay fresher and less soggy this way.

Freezing

While the pesto mayo and mozzarella don’t freeze well, you can freeze grilled portobello caps and onions if needed. Tightly wrap each in plastic, place in a freezer-safe bag, and freeze up to a month—just know the texture may soften a bit after thawing.

Reheating

To reheat, warm the mushroom caps (and onions) gently in a covered skillet over medium-low heat or pop them on a baking sheet in a 350°F oven until heated through. Add cheese at the end so it gets melty, then reassemble your burger fresh with pesto mayo and all the fixings.

FAQs

Final Thoughts

If you’re looking to wow your taste buds (and your veggie burger skeptics!), the Portobello Mushroom Burger with Mozzarella, Roasted Peppers and Pesto Mayo is a truly tasty showstopper. Grab your ingredients, fire up the grill, and enjoy a colorful, flavor-packed burger that’s just as fun to make as it is to eat. I can’t wait for you to take that first, glorious bite!

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