In a bowl, mix together the ricotta, Swiss chard, sun-dried and fresh tomatoes, and egg.
Season well with salt and black pepper.
Lay 2 sheets of filo pastry, one on top of the other, in the cake tin, letting them hang over the edge on two sides.
Next, lay 2 more sheets of filo at right angles to the first layer.
Continue in this way until you have 8 sheets for the base of the pie.
Spoon the ricotta mixture into the pie. Fold in the edges of the pastry, and top the pie with the remaining 4 sheets of filo pastry, tucking them in neatly.
Brush all over with the melted butter, and bake in the oven for 20–30 minutes until golden and crisp.
Serve hot with a crisp green salad and some boiled salad potatoes.