Ingredients:

  • 4 large portobello mushroom caps (about 4-5 inches diameter), stems removed
  • 2 tablespoons olive oil (30 ml)
  • 2 tablespoons balsamic vinegar (30 ml)
  • 1 tablespoon soy sauce (15 ml) (or tamari for gluten-free)
  • 1 clove garlic, minced
  • 1 teaspoon dried thyme
  • 1/2 teaspoon black pepper
  • 1/4 teaspoon salt
  • 4 burger buns of your choice (brioche, whole wheat, etc.)
  • 4 slices provolone cheese (or mozzarella, or your favourite)
  • 1/2 cup mayonnaise (120 ml)
  • 2 tablespoons balsamic glaze (store-bought or homemade)
  • 4 cups arugula (rocket) (or spinach, or mixed greens)
  • 1 large tomato, sliced
  • 1/2 red onion, thinly sliced
  • Optional: Avocado slices, grilled red peppers

Instructions:

  1. Whisk together olive oil, balsamic vinegar, soy sauce, minced garlic, thyme, salt, and pepper in a small bowl.
  2. Place portobello caps in a shallow dish. Brush generously with the marinade, ensuring they are well coated. Let marinate for at least 30 minutes, flipping halfway.
  3. Preheat your grill to medium heat (about 350-400°F / 175-200°C).
  4. Place marinated portobello caps gill-side up on the preheated grill. Cook for about 5-7 minutes. Flip and cook for another 5-7 minutes, or until tender and slightly charred. During the last minute of cooking, place a slice of cheese on each mushroom cap to melt.
  5. Lightly toast the burger buns on the grill or in a toaster (optional).
  6. Spread mayonnaise on the top and bottom buns. Layer with arugula, tomato slices, red onion slices, and the grilled portobello with melted cheese. Drizzle with balsamic glaze. Add any other desired toppings (e.g. avocado, grilled peppers).
  7. Serve your gourmet portobello burger immediately!