Recipe: Grilled Portobello Burgers

Last updated: October 26, 2021, at 12:17 p.m. PT

Originally published: August 5, 2021, at 12:32 p.m. PT

Portobello burger on a bun with onion and tomato slices and a slice of melted cheese.


  • 2 tablespoons balsamic vinegar
  • 1 tablespoon tamari or soy sauce
  • 1 tablespoon avocado oil
  • 1 teaspoon dried oregano
  • 1 ½ teaspoon steak seasoning blend (recipe below)
  • 4 large portobello mushrooms, stems removed
  • 1 red onion, cut into thick slices 
  • 4 slices swiss cheese
  • 4 whole-wheat hamburger buns
  • 1 large tomato, sliced
  • Leaf lettuce
  • 1 avocado, sliced


  1. Whisk together the vinegar, tamari, oil, oregano, and steak seasoning in a shallow dish.
  2. Add the mushrooms to the marinade and spoon or brush the marinade evenly over both sides of the mushroom caps.
  3. Set aside to marinate for at least 20 minutes or up to an hour.
  4. Heat your grill to medium heat and brush grill grates with avocado oil.
  5. Grill the mushrooms and onion slices for about 5 minutes on each side, brushing with the reserved marinade.
  6. During the last minute of grilling, top the mushrooms with cheese and toast the buns.
  7. Top the bun with the grilled mushroom and onions and top with tomato, lettuce, avocado, and any other toppings you’d like.

Serves: 4


Combine 2 tablespoons salt, 1 ½ tablespoons each: black pepper, garlic powder, onion powder, AND 1 tablespoon each: ground coriander, dried parsley AND 1 ½ teaspoons each: smoked paprika, dried mustard and red pepper flakes. Store in an airtight container.

Category: Recipes