Work on one sheet at a time. Spread it on a dry flat surface and lightly brush half of it with oil, fold it, and brush half of it and fold again. Now you have a piece with 4 layers.
Put 2 tablespoons of filling along the narrower side, leaving about 1in/2.5cm from the top and both sides clear of the filling. Brush the rest of the piece with oil. Turn the top onto