To make the filling melt the butter in a large frying pan. Chop and sauté the onion over a medium heat until soft. Sprinkle the flour over the onions and add the spinach, allowing it to wilt. The flour should help absorb the extra liquid from the spinach. Crumble in the feta and stir in the cream cheese and nutmeg. Season with salt and pepper.
Roll out the pastry on a lightly floured surface. Make a sort of pasty, by piling the filling on half the pastry. Leave an edge that you can press together to seal it when you fold the other half of the pastry over to close the pie. It makes things easier if you have a small folding grid to lay the pastry in – easier to flip.
Bake on an indirect fire until the pastry is golden on both sides, about 25–30 minutes.
Recipes from Girls on Fire by Camilla Comins, published by Russel Wasserfall Food, an imprint of Jacana Media.