4 portobello mushroom caps
2 tbsp balsamic vinegar
1 tbsp soy sauce
1 tablespoons olive oil
1 tbsp chopped rosemary
1-1/2 tsp steak seasoning
4 thick slices red onion
4 oz reduced fat Swiss, sliced thin cheese or goats’ cheese
4 thin slices tomato
1/2 avocado, sliced thin
4 gluten free pittas
1. In a large bowl, whisk together vinegar, soy sauce, oil, rosemary, and 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.
2. 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.
3. 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 pittas until toasted.
4. To finish, place the spinach and grilled portobello mushrooms on the buns and top with the grilled onions, sliced tomato and avocado.