Preheat the oven to 200°C. Wash your spinach and place it in a large colander. Boil a full kettle of water and slowly pour over the spinach, making sure all are getting blanched. Leave to cool down.
When cool enough to handle, squeeze out all the moisture with your hands. You should be left with a large handful of compacted spinach. Place on a chopping board and chop up roughly.
Heat 2 tbsp of vegetable oil to a pan. Add brown onion, spring onion and garlic and cook on medium heat for 4 minutes.
Add the spinach and cook for another minute. Then take off the heat and leave to cool down.
In a separate large bowl, mix together cream cheese, an egg, a pinch of nutmeg, dill, mint, lemon zest and salt and pepper. Add the cooled spinach and mix to combine. Crumble the feta in chunks and mix carefully not to break it up too much.
Lay your filo pastry sheets. Add a third of the spinach mixture on each sheet and spread along the longer edge of the pastry. Then roll into a tube (see photos above).
Roll the tube into a wheel. Then repeat with the other two sheets, wrapping the tubes around the first wheel.
Lightly brush the top of the wheel with the olive oil, then sprinkle some nigella seeds on top.
Bake in the oven for 25-30 minutes or until the top of the wheel turns golden brown.
Serve it with a fresh cucumber and tomato salad if you like.