Stuffed Portobello Mushroom Burger

We set out to make a great tasting grilled portobello mushroom burger that even a meat lover would love. The mushrooms are marinated then grilled and topped with melted Swiss Cheese, grilled red onion,  tomatoes, spinach, and avocado.

You want to give the mushrooms a meaty flavour, so marinate them with balsamic, soy sauce and Montreal steak seasoning. These were so good, perfect for meatless Mondays or any night of the week.

Ingredients:

  • 4 portobello mushroom caps
  • 2 tbsp balsamic vinegar
  • 1 tbsp low sodium soy sauce
  • 1 tablespoons olive oil
  • 1 tbsp chopped rosemary
  • 1-1/2 tsp steak seasoning like Montreal Steak Grill Mates
  • 4 thick slices red onion
  • 4 oz reduced fat Swiss, sliced thin
  • 4 thin slices tomato
  • 1/2 avocado, sliced thin
  • Baby spinach
  • 4 whole wheat low calorie buns

Directions:

  1. In a large bowl, whisk together vinegar, soy sauce, oil, rosemary, and Montreal steak seasoning.
  2. Place the mushroom caps in the bowl and toss with sauce, using a spoon to evenly coat. Let stand at room temperature for 20 to 30 minutes, turning a few times.
  3. Heat the grill or indoor grill pan over medium heat. When hot, brush the grate with oil or lightly spray the grill pan.
  4. Place the mushrooms on the grill, reserving marinade for basting. Grill for 5 to 7 minutes on each side, or until tender, brushing with marinade frequently.
  5. Top the mushrooms with cheese during the last minute of cooking.
  6. While the mushrooms cook, grill the onions about 1 minute on each side and grill the buns until toasted.
  7. To finish, place the spinach and grilled portobello mushrooms on the buns and top with the grilled onions, sliced tomato and avocado.