Slice the zucchini into ¼ inch thick rounds. Heat the olive oil in a large frying pan and cook the zucchini in batches for about 2 minutes each side. Season with salt and pepper.
Place the cooked zucchini on a large baking sheet and top with the tomato purée and grated mozzarella.
Cook this in the oven for about 2-3 minutes or until the cheese has melted. Remove from the oven and sprinkle with Italian seasoning and freshly ground pepper before serving.