Why You’ll Love This Grilled Portobello Burger
Protein is trending, and for good reason—it’s essential. But in the heat of summer, I often reach for lighter, more plant-forward meals. This is one of my favorite seasonal swaps. The portobello mushroom caps give you that satisfying bite and umami flavor you’d expect from a beef burger, while still feeling light and nourishing.
The marinade infuses the mushrooms with garlicky tang, the crosshatch technique helps with moisture and texture, and the garlic-chive aioli ties it all together with a creamy zing. It’s the kind of burger you can dress up or down depending on the day—add a slice of provolone or Havarti if you want a protein boost. Or enjoy it as-is with a pile of arugula on top. Either way, it’s totally satisfying.
If you’re exploring more summer mains, try my wild salmon burgers or black bean burgers next.
Ingredients You’ll Need
- Portobello mushrooms – Meaty and umami-rich, these are the perfect stand-in for a burger patty. Removing the gills helps prevent sogginess.
- Olive oil + red wine vinegar – This simple combo makes a bright and flavorful marinade.
- Garlic, salt, and pepper – Boosts depth in the marinade.
- Red onion slices – Grilled until lightly charred, they add a smoky sweetness.
- Garlic-chive aioli – Adds richness and a punch of flavor. A simple mix of mayo, lemon zest, garlic, and chives.
- Arugula – Fresh and peppery, perfect for balance.
- Optional cheese – Havarti or provolone both melt beautifully.
- Burger buns – Toasted is best. Brioche or whole wheat work great.
How to Make This Grilled Portobello Burger
Step 1: Clean the mushrooms and remove stems and gills. Score the top of each cap in a shallow crosshatch pattern to help with texture and flavor absorption.
Step 2: In a large resealable bag, combine olive oil, vinegar, garlic, salt, and pepper. Add mushrooms and marinate at room temp for 30 to 60 minutes.
Step 3: Skewer red onion slices with a toothpick to hold the layers together. Brush with leftover marinade or a drizzle of olive oil.
Step 4: Preheat your grill to medium-high (400–450°F). Place mushrooms and onions on the grill, gill-side up. Cover and cook for 4–6 minutes.
Step 5: Flip carefully and cook another 3–4 minutes. The onions may finish slightly earlier—watch closely.
Step 6: Remove from the grill and let rest gill-side up. Toast buns cut-side down for 1–2 minutes. Make the aioli.
Step 7: Build your burger: spread garlic-chive aioli on the bottom bun, add the grilled mushroom (gill side up), optional cheese, onion slice, arugula, and top bun. Serve immediately.
Tips for the Best Grilled Portobello Burgers
- Crosshatch the caps to help them release moisture and grill evenly.
- Grill gill-side up first to let excess liquid evaporate.
- Rest mushrooms gill-side up after cooking to avoid sogginess.
- Toast the buns—this prevents them from getting soggy and adds flavor.
- Optional cheese: Havarti or provolone both melt well and complement the meaty flavor of the mushrooms.
Recipe FAQs
Score the tops, grill gill-side up first, and rest them that way after cooking. This helps release moisture and keeps the texture meaty.
Yes. The gills can become muddy and contribute to sogginess. Removing them also makes space for fillings.
Yes. Roast at 425°F for about 10–12 minutes per side on a parchment-lined baking sheet.
Marinate the mushrooms ahead of time, but grill just before serving for the best flavor and texture.
This grilled portobello burger is hearty, meaty, and full of flavor—everything you want in a summer main without the meat. Whether you add cheese or keep it simple with arugula and aioli, it’s always satisfying.
Let me know if you give it a try and how you dressed it up! If you’re into light and flavorful mains, try my baked fried chicken or parmesan ranch dressing with summer veggies next.
Try These Mushroom Recipes
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Grilled Portobello Burger (with Garlic-Chive Aioli)
Ingredients
- 4 portobello mushrooms, 4-5 inches in diameter, stems and gills removed, caps wiped clean with a damp paper towel
- ½ cup extra-virgin olive oil
- 3 Tablespoons red wine vinegar
- 1 garlic clove, minced
- 1 teaspoon kosher salt
- ½ teaspoon freshly ground black pepper
- 4 ½-inch thick slices of red onion
- Condiments that I like, but feel free to do your own: arugula, Garlic-Chive Aioli (see recipe below), Havarti or Provolone
- 4 burger buns toasted
Garlic-Chive Aioli
- 1 clove garlic, chopped
- Big pinch salt
- ½ Tablespoon extra-virgin olive oil
- ¼ cup mayonnaise
- Zest of ⅓ of a lemon
- Freshly ground black pepper to taste
- 2 Tablespoons fresh chives, finely chopped (or your favorite herb)
- Garlic-Chive Aioli
- 1 clove garlic, chopped
- Big pinch salt
- ½ Tablespoon extra-virgin olive oil
- ¼ cup mayonnaise
- Zest of ⅓ of a lemon
- Freshly ground black pepper to taste
- 2 Tablespoons fresh chives, finely chopped (or your favorite herb)
Instructions
- Using the tip of a paring knife, cut 1/16-inch-deep slits on top of each mushroom in a crosshatch pattern, each slit being ½ inch apart.
- Combine olive oil, red wine vinegar, garlic, salt and pepper in a 1-gallon resealable bag. Add the mushrooms and seal bag to marinate for 30 to 60 minutes at room temperature.
- Prepare the onions: push 1 toothpick through each onion slice horizontally to keep all the layers together. It makes it easier to hold the onion together when flipping on the grill. Brush both sides with mushroom marinade (or just use olive oil, salt and pepper.)
- Preheat the grill over medium-high heat. All grills are different, so you’re looking for a temp in the 400-450 degrees F range.
- Place onions and mushrooms on grill, gill side up. Cook covered for 4-6 minutes, until they are slightly charred and have begun to release some liquid. Flip mushrooms and onion and cook for 3-4 minutes. Watch both early. It is possible the onions might be done before the mushrooms.
- Transfer to a platter. Discard the toothpicks and place mushrooms gill side up. Place desired toppings inside the mushroom, finishing with the onion.
- Grill buns until lightly toasted. Spread garlic-chive aioli evenly on the button bun and layer the mushroom and onion, finishing with arugula. Top with top buns and serve.
Garlic Chive Aioli
- Mash the garlic with some salt on a cutting board. I do this with the flat side of a knife blade. Transfer to a small bowl and add remaining ingredients. Taste for seasoning. Can be made ahead and refrigerated for up to 2 days.
Notes
- Crosshatch the caps to help them release moisture and grill evenly.
- Grill gill-side up first to let excess liquid evaporate.
- Rest mushrooms gill-side up after cooking to avoid sogginess.
- Toast the buns—this prevents them from getting soggy and adds flavor.
- Optional cheese: Havarti or provolone both melt well and complement the meaty flavor of the mushrooms.
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