Preheat the grill. Spread two teaspoons tomato puree over one side of each pitta bread. Arrange on the grill rack and top with the sliced tomatoes. Sprinkle with the mixed herbs and grated cheese.
Grill for three or four minutes, until the cheese is melted and bubbling.
Season with a little black pepper, then serve, topped with the olives and Parma Ham slices, scattered with a few basil leaves.
