Place the dough sheets next to each other and allow to thaw at room temperature. Drain tomatoes and cut into cubes, mix with cream cheese, mustard and oregano, season with salt and pepper
Place puff pastry slices on top of each other and roll out rectangularly (approx. 20 x 30 cm) on a floured work surface. Cut into 6 squares (each 10 x 10 cm), prick several times with a fork. Place the squares on a baking tray lined with baking paper and bake in a preheated oven (electric cooker: 225 °C/ convection oven: 200 °C/ gas: see manufacturer) for 5-7 minutes
Drain the sardines, divide the fillets, removing the bones. Take the baking tray out of the oven, spread the dough squares with cream cheese, leaving about 1 cm free at the edges. Spread the sardines over the tartlets. Sprinkle each tartlet with 1 tsp. olive oil. Bake at the same temperature for about 10 minutes
Slice or grate the parmesan. Wash the rocket and drain well. Remove the tartlets from the oven, sprinkle with Parmesan and rocket
Waiting time approx. 30 minutes