Heat olive oil in a frying pan over medium-low heat. Add the chopped onions and cook slowly until soft and translucent.
Stir in the paprika, salt and pepper, then remove from heat and allow to cool completely.
Once cooled, mix in the eggs (and feta, if using), then set aside.
Preheat the oven to 180°C (fan-forced). Combine olive oil and melted butter, then lightly brush a baking dish with the mixture.
Lay half the filo sheets into the dish, brushing each sheet with the butter and oil mixture before adding the next.
Spread the onion filling evenly over the base.
Layer the remaining filo sheets on top, again brushing each one as you go. Finish with an extra brush of butter and oil.
Using a sharp knife, score the top layer into your preferred serving portions - this helps prevent the pastry from crumbling after baking.
Bake for 35–40 minutes, or until golden and crisp.
Allow to cool slightly before slicing and serving.
6 servings