Trim any coarse stems from the spinach, then wash the leaves thoroughly, roughly chop them and place in a large saucepan with just a little water clinging to the leaves. Cover and cook over low heat for 5 minutes, or until the leaves have wilted. Drain well and allow to cool slightly. Squeeze tightly to remove the excess water.
Heat the oil in a heavy-based frying pan. Add the onion and cook over low heat for 10 minutes, or until tender and golden. Add the spring onion and cook for 3 minutes. Remove from the heat. Stir in the spinach, parsley, dill, nutmeg, parmesan, feta, ricotta and egg. Season well.
Preheat the oven to 180°C (350°F/Gas 4). Lightly grease two baking trays. Combine the butter with the extra oil. Work with three sheets of pastry at a time, keeping the rest covered with a damp tea towel. Brush each sheet with butter mixture and layer them and cut in half lengthways.
Place 4tablespoons of the filling on an angle at the end of each strip. Fold the pastry over to enclose the filling and form a triangle. Continue folding the triangle over until you reach the end of the pastry. Put the triangles on the baking trays and brush with the remaining butter mixture. Bake for 20–25 minutes, or until the pastry is golden brown.