Portobello Mushroom Burger with Mozzarella, Roasted Peppers and Pesto Mayo

Bahan-bahan (4 porsi)

• 2 tablespoons jarred or homemade pesto
• 2 tablespoons light mayo
• 4 portobello mushroom caps
• 2 tbsp balsamic vinegar
• 1 tbsp low sodium soy sauce
• 1 tablespoons olive oil
• 1 -1/2 tsp steak seasoning like Montreal Steak Grill Mates
• 4 thick slices red onion
• 4 oz fresh mozzarella (sliced thin)
• 1 roasted red pepper (jarred or homemade sliced)
• 4 whole wheat low calorie buns (I used Martin)