Grilled Portobello Burger (with Garlic-Chive Aioli)
Craving something meaty but plant-based? This grilled portobello burger delivers bold flavor and satisfying texture—perfect for summer grilling without the heaviness of meat. Juicy mushrooms are marinated, char-grilled, and layered with garlic-chive aioli, grilled onions, and arugula for a hearty vegetarian main everyone will love.
Servings: 4
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.