First, make the stuffing by stirring the baking soda with the yoghurt. To them add the beaten egg and beat the mixture again until homogeneous.
Next add the crumbled feta cheese to it.
In an oiled tray, arrange 3 phyllo pastry sheets, while sprinkling each one with oil.
Put stuffing, another 3 sheets with oil, stuffing and so on until out of ingredients, while finishing off with sheets. Cut it up like a cake.
First pour hot butter on top, then the mixture of milk and eggs.
Put in the oven and bake until reddened.