Carefully unroll the filo pastry. Cover with some damp sheets of kitchen paper to stop it drying out. Brush the inside of a springform cake tin with some melted butter. Take a sheet of pastry drape you're your cake tin so that some of the pastry hangs over the side. Keep placing the pastry pieces in the tin until you have roughly three layers, then spoon in the filling. Pull the sides into the middle, scrunch up and make sure the filling is covered, brushing each layer with melted butter as you go.
Cook the pie for 30 - 40 minutes until the pastry is crisp and golden brown. Leave to cool, remove from the cake tin, then slice into wedges and serve with salad.