Mix flour with eggs, a pinch of salt and milk to obtain a firm mixture. Leave it to stand for 15 minutes.
Wash the spinach (or use the already washed ones), cook with few water for 5-6 minutes. Drain, squeeze and chop. Mince the onion, let it brown on a high flame with butter and add the spinach.
Add salt and pepper and let it flavour for 4-5 minutes stirring. Spread the sheet of pastry (2-3 mm thick) and make some disks (about 8 mm diameter) with an upside down glass.
Put a tablespoon of spinach mixture in the centre of each disk and sprinkled with Parmesan. Cover the mixture with the disk forming a half moon and press the contour with a fork.
