Remove the puff pastry from the fridge and leave to stand at room temperature for 10 minutes.
Preheat the oven to gas 6, 200°C, fan 180°C and line a large baking tray with a piece of nonstick baking paper.
Unroll the pastry onto the baking tray. Score a 1cm (1⁄2in) border around the edge of the pastry with a sharp knife.
In a bowl, mix the ricotta, 2 tbsp of finely grated Grana Padano and the egg. Add the chopped basil (reserving some to scatter over at the end, if liked) and season well.
Spread the mixture over the pastry, avoiding the border.
Top the tart with the courgette slices and scatter over the remaining cheese.
Bake for 20-25 minutes.
Sprinkle over the pine nuts and return the tart to the oven for 5 minutes, until golden brown.