How to make
In a pot, melt a little of the butter and saute the pre-cleaned and chopped spinach. Once the spinach is tender, remove the pot from the heat and add the crumbled feta cheese.
In a greased tray, put the first sheet, smear it thoroughly with melted butter. Spread some spinach on top, sprinkle with chopped walnuts and put the second sheet on.
Continue in this order until you've placed the last sheet. Using a fork, or other sharp utensil, make holes all over the entire pastry. Mix the yoghurt with baking soda.
Top the pastry with the beaten eggs, milk and yogurt. Bake in a preheated oven on medium heat, until ready.