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.
- 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
- In a large bowl, whisk together vinegar, soy sauce, oil, rosemary, and Montreal steak seasoning.
- 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.
- Heat the grill or indoor grill pan over medium heat. When hot, brush the grate with oil or lightly spray the grill pan.
- 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.
- Top the mushrooms with cheese during the last minute of cooking.
- While the mushrooms cook, grill the onions about 1 minute on each side and grill the buns until toasted.
- To finish, place the spinach and grilled portobello mushrooms on the buns and top with the grilled onions, sliced tomato and avocado.