Prep. time: 20 minutes
Cooking time: 1 hour with regular pastry or 20 minutes with phyllo

 Making the pastry

1. Energetically combine all the ingredients for the pastry to make a smooth elastic dough; divide into 18 parts;
2. roll out each part with a rolling pin to form a disk 20 cm (8") in diameter; brush with oil.

Assembly and baking

1. Cook the spinach in boiling water; drain and dry by pressing the water out with your hands;
2. sauté the onion in the butter until softened; let cool; beat 2 eggs in a bowl with a little milk; add the grated Parmesan, spinach and onion and season with salt;
3. spread 9 pieces of pastry in the bottom of a tart mold, letting them come up the sides; pour in half of the spinach mixture; place the hardboiled eggs in a circle; cover with the remaining spinach;
4. cover everything with 9 pieces of pastry, folding the edges in towards the middle;
5. brush the tart with a little oil and a few drops of water;
6. place on a non-stick or lightly buttered baking sheet; place in a preheated 200° C (400° F) oven for one hour; if the tart is browning too quickly, cover with a sheet of aluminum foil.

If using phyllo pastry

1. Brush each sheet with warm oil;
2. reduce the baking time to 20 minutes.