Preheat your oven to 200°C (gas mark 6). Unroll the puff pastry, cutting it into 6 even rectangles. Score a 1cm border around the edge of each rectangle with a sharp knife, then chill while you prepare the filling.

In a mixing bowl, combine the ricotta, 25g of sliced olives, and all but 1 tablespoon of chopped oregano leaves. Season the mixture to taste.

Spread 4 tablespoons of black olive tapenade or red pesto onto the center of each pastry rectangle. Layer the ricotta mixture on top and finish with sliced tomatoes. Scatter the reserved black olives on top, season, and prepare to bake.

Place the baking tray in the oven and bake for 25-30 minutes or until the pastry is golden brown and puffed.

Once baked, sprinkle the reserved oregano leaves on top. Serve warm or allow to cool to room temperature.