Bring a pan of boiling water to the boil and blanch the watercress and herbs for 1 minute, then drain. Cool, then squeeze out any excess water
Mix with the feta, eggs and seasoning
Brush the inside of the tin with olive oil, then lay a few sheets of filo on top, overlapping and brushing them with oil
Fill with the cheese and herb filling, folding the overhanging pastry sheets over the top
Top with extra scrunched up filo, brushing each sheet generously with oil
Bake at 200°C for 20 minutes, or until golden brown
