Preheat the oven at 180°C. Melt the butter and butter 4 of the pastry sheets one by one. Place them in a 26cm diameter baking pan. In the blender, beat the eggs, yoghurt, milk, salt and pepper. Add the herbs, minced, and all the cheese, and keep beating for 1 min until the cheese is all broken down. Butter the remaining sheets and place them on top, carefully sealing the pie with a sharp knife; bake for approx. 30-35 min.
Leave it to cool down for a little and serve. It is also tasty lukewarm, at room temperature.