Preheat oven to 190C

In a bowl, combine the feta, ricotta, cornichons, egg, spinach, salt and pepper and mix well.

Take on sheet of pastry and liberally brush one side with melted butter, then fold pastry onto of itself with butter on the inside. Brush the topside layer with butter.

Take another sheet and also liberally brush one side with melted butter, then fold pastry onto of itself with butter on the inside. Place this on top of the buttered side of the other folded pastry piece.

Cut the layered pastry into two lengthwise.

Put a heaped tablespoonful of mixture at the bottom of a pastry strip. Fold the pastry across into a triangle.

Keep folding the triangle-shaped filling up the strip until it is used up. Brush on extra butter to stick down the end, if required. 

Place the triangles on an oven tray covered with baking paper. Brush the top of the triangles with butter and sprinkle with sesame seeds if desired.
 
Bake at 190C for 20-25 minutes until pastry is crisp and slightly browned