Blanch, drain and finely chop spinach. Mix spinach, quark, feta, nutmeg and pepper in a bowl. Lay out 1 sheet of filo, brush with melted butter, fold filo length ways into thirds. Place a dessert spoon of the spinach & quark mixture on the bottom corner of the filo. Fold the bottom corner over so that the bottom edge joins the side of the filo to make a triangle. Brush the remainder of the pastry with a little butter and continue folding the spinach, quark filled filo, keeping the triangular shape all the way to the top. Brush the outside with butter and bake in moderate oven until golden.