Preheat oven to 180 degrees Celsius. lightly brush a 23cm pie plate with some of the butter.
Toss pumpkin in roasting pan with olive oil and season to taste. Bake for 30-40 minutes until tender. Removed and cool slightly.
Working with one sheet of filo at a time, fold in half and brush with butter. Place in prepared dish. Repeat with the rest of the pastry and butter, overlapping to completely cover the dish.
Bake for 5 minutes until just starting to colour and become crisp. Remove and cool. Place pumpkin in a bowl with ricotta and sage. Roughly mash to combine. Stir in eggs and flour, and season to taste. Pour mixture into prepared pastry case. Sprinkle with parmesan cheese.
Top with buttered scrunched filo pastry sheets.
Bake for 20-25 minutes until filling is set. Stand for 5 minutes before cutting into wedges. Serve with rocket salad.