Preheat oven to 200°C. Roll the puff pastry out on a floured board and cut four 10cm squares. With a sharp knife mark a square, one centimeter in from the edge (as in a picture frame), and place them on a baking frame and bake for 12 minutes. Then remove the top layers of the inner square carefully, leaving the base intact. Pop back in the oven for 3 minutes to dry out and then cool.
Cut the cherry tomatoes in half and place in a roasting tin, season with salt and pepper and roast for 10-15 minutes, or until just cooked. Cut the plum tomatoes into quarters, de-seed and slice into thirds.
To assemble: spread two teaspoons of tomato puree into each pastry case. Toss the rocket, cherry tomatoes, plum tomatoes, and black olives together with the olive oil.
Season with salt and pepper and pile onto the pastry cases. Top with the Parmesan shavings.