• Heat the oven to 200C/fan 180C/gas 6.
  • Cook the onions in a large knob of butter until soft and turning golden.
  • Add the garlic and cook for a couple of minutes.
  • Add the spinach in batches and cook until wilted.
  • Cool, then tip into a bowl (leaving behind any excess liquid from the spinach) and mix in the nutmeg, feta, eggs and season.
  • Melt 30g more butter, and butter a non-stick springform cake tin, about 20-22cm.
  • Put the first sheet of filo in the tin and brush with butter, letting the excess hang over the sides. Keep going with the rest of the sheets, turning a little before adding each additional pastry sheet and brushing all over with butter.
  • When all the pastry is used up, tip in the filling and fold over the excess pastry to cover.
  • Butter the top then bake in the oven for about 20-30 minutes until the filo is crisp and golden.
  • Leave for 5 minutes before turning out and cutting into wedges to serve.