Line a large platter with romaine leaves. Arrange steak in the center and surround with mushrooms, tomatoes, and cucumber. Scatter cheese over vegetables.

In a jar with a lid, or in a bowl, mix olive oil, vinegar, and any meat and mushroom juices.

Pour oil and vinegar dressing over vegetables. Cut pocket breads in half. To eat, fill pockets with meat and vegetables, adding salt and pepper to taste.