Preheat oven to 180ºC. Line the base of a 20 centimetre springform tin with baking paper.
Heat olive oil in a fry pan, add onion and garlic and saute until translucent, approximately five minutes. Set aside to cool for a further five minutes.
Meanwhile, squeeze as much water out of the spinach as possible. Add to a large bowl along with ricotta, artichoke, pine nuts, nutmeg, salt, pepper and eggs. Add in cooled onion and garlic and stir together until well combined.
Brush springform tin with melted butter. Carefully layer filo pastry allowing parts to spill over the edge of the tin. Brush with butter in between each layer.
Pour in ricotta mixture. Fold over filo pastry hanging over the edge to cover the top of the pie. Brush with a little more butter and sprinkle with sesame seeds.
Bake for 30 minutes until filo is golden and crunchy on top. Serve with a fresh side salad.