Preheat the oven to 200°C/fan 180°C/gas mark 6. Roll out the pastry into a large rectangle ½cm thick. Cut to a 30cm x 21cm rectangle and use a knife to mark out a border about 2½cm from the edge. Using a sharp knife, mark a lattice pattern on the borders, then brush with the egg. Place on a baking tray in the fridge.
Meanwhile, lightly mix together the soft cheese, lemon juice and 2 tbsp parmesan in a bowl. Season with plenty of freshly ground black pepper, then spread over the pastry. Press the peas into the tart and pile on the courgette ribbons. Scatter over the spring onions and the remaining parmesan.
Brush with the oil, then bake for 20-25 minutes until golden and risen. Serve warm or cold.