- 4 Portobello mushroom caps, gills removed
- 4 tablespoons olive oil
- 1/2 teaspoon salt
- 1/4 teaspoon freshly ground black pepper
- 1 small avocado, peeled, pitted and thinly sliced
- 1/2 cup roasted red peppers, thinly sliced
- 1/2 cup mixed green queen olives and black ripe olives, sliced (or your favorite olive)
- Garlic-Basil Mayo
- 8 tablespoons Balsamic Onions
- 1 cup baby spinach
- 4 hamburger buns or Kaiser rolls
Preheat a grill to medium-high.
Drizzle the olive oil on both sides of the mushroom caps and season with the salt and pepper. Transfer the mushrooms to the grill and cook for 4 to 5 minutes per side, or until tender.
Assemble the burgers by spreading 2 teaspoons of the Garlic-Basil Mayo on the bottom half of the buns. Arrange one quarter of the avocado slices on each bottom bun and then add the roasted red peppers and olives. Place the mushroom caps on top of the olives. Spread 2 tablespoons of the Balsamic Onions on top of each mushroom. Arrange 1/4 cup of the baby spinach on top of the Balsamic Onions. Place the bun tops on each burger. Serve immediately.