Preheat the oven to 200°C, fan 180°C, gas 6.
Roll out the pastry into a large rectangle 0.5cm thick. Cut to a 30cm x 21cm rectangle and use a knife to mark out a border about 2.5cm from the edge. Using a sharp knife, mark a lattice pattern on the borders, then brush with the egg. Place on a baking tray and refrigerate while you prepare the other ingredients.
In a bowl, lightly mix together the soft cheese, lemon juice and 2 tablespoons of the parmesan. 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 (they shrink down during cooking). Scatter over the spring onions and the remaining parmesan.