Preheat oven to 350 degrees F. Arrange zucchini halves on 2 rimmed baking sheets lined with parchment paper.In a small bowl, mix to combine Parmesan cheese, oregano (thyme), salt and black pepper. Top each zucchini slice with 1 - 1.5 tbsp of cheese-herb mixture spreading evenly. Bake for 15 minutes. Then broil on High for 4 - 5 minutes or until cheese turns crispy and golden. Serve warm or cold.