Line a large baking sheet with nonstick baking paper. Roll out the pastry on a lightly floured work surface to 2.5 mm (⅛ inch) thick. Use a 12 cm (5 inch) round cutter to stamp out 6 rounds and lay on the prepared baking sheet.
Spread 1 tablespoon sun-dried tomato paste over each pastry round. In a small bowl, mix together the tomatoes, mozzarella, olives, garlic, oregano and pine nuts and season well with salt and pepper. Divide the mixture between the pastry rounds.
Drizzle a little olive oil over the tartlets and bake in a preheated oven, 200°C (400°F), Gas Mark 6, for 20 minutes or until the pastry is golden. Serve immediately with mixed salad leaves.