Squeeze the excess moisture from the spinach and lay out on kitchen paper.
Heat the oil in a small frying pan and add the onion and garlic. Cook, stirring, over a medium heat until the onion is tender.
Let cool, then transfer to a large bowl. Add the spinach, chickpeas, ricotta, eggs and dill, and mix well.
Preheat the oven to 200°C, fan 180°C, gas 6. Grease a 22cm springform tin.
Brush each sheet of filo with melted butter. Fold in half to enclose the buttered side, then gently press into the base and sides of the tin. Pour in the spinach mix then top with the Greek-style cheese. Gently push down the filo around the sides of the tin to neaten the tart. 6. Place the tin on an oven tray and bake for about 40 minutes or until golden and set. Allow to cool in the tin.
Cook's tip: if you prefer a thicker crust, simply replace the filo pastry with 1 x 375g pack ready-rolled shortcrust pastry. Line the tin and bake blind for 15 minutes before pouring in the spinach mixture.