1 Mix the flour and salt, add the oil and 225-250 ml water and work to a dough. Knead the dough on a work surface for at least 10 minutes until it has an elastic consistency. Wrap in foil or clingfilm and leave to rest until the filling is ready.
2 Sort and wash the spinach and put into a pan dripping wet. Heat over a high heat until it wilts, then drain well and chop finely. Shell the hard-boiled eggs.
3 Peel and finely chop the onion and garlic and sweat in oil until translucent. Leave to cool, then mix in the spinach and herbs. Crumble the ricotta finely and mix in also. Season with salt, pepper and nutmeg.
4 Separate the eggs. Beat the whites until stiff. Beat the yolks with a good pinch of salt and the cream. Fold the spinach and ricotta mixture into the egg yolk mixture and fold in the beaten egg whites.
5 On a floured work surface roll out two thirds of the pastry to a thickness of 3-4 mm and use to line a greased and floured dish. Put half of the filling into the lined dish, add the hard-boiled eggs, pressing in lightly and cover with the rest of the filling.
6 Roll out the remaining pastry, place over the filling and press the edges of the pastry together firmly.
7 Bake in a preheated oven (180°C | 350F | gas 4 with top and bottom heat) for about 1 hour, until golden brown (cover with foil or baking parchment if the pastry browns too quickly).
8 Take out and turn out onto a cake plate. Serve warm or cold.