Remove the tomatoes from the vine, wash and thickly slice. Preheat the oven to 200°C/gas mark 6. Mix the soft cheese and mustard in a small bowl.
Lay the pastry on a non-stick or lightly greased baking sheet. Trim off any excess and make a raised border the thickness of two fingers.
Spread the soft cheese and mustard mix on the pastry and arrange the tomato slices on top.
Grate the parmesan cheese over the tart. Season, then decorate with olives. Bake in the oven for 30 minutes or until the pastry is golden and the tomatoes are cooked.