Preheat the oven to 200 ºC. Take the slices of puff pastry out of the freezer and let them thaw.
Use a cooking ring or cutting utensil to cut 8 rounds from the dough. Spoon ½ tablespoon of tomato tapenade in the centre of each dough circle, place a gratin on top.
Place the gratin galettes in the oven for about 20 minutes until golden brown and cooked through.
Serve the gratin on 4 nice plates top each gratin galette with a sun-dried tomato.