Pour 2/5 cup (100 g) of sifted flour in a bowl and knead it with the crumbled yeast (not effervescent).
Next, add the water and yoghurt, salt. Knead a dough with the remaining flour. It needs to be medium hard. Divide the dough into 10 balls immediately; cover them with a towel.
Take 1 ball, roll it out into a sheet the size of the dessert plate. Smear it with oil and place small lumps of lard in the middle.
Roll out another ball into a sheet. Place it atop the 1st. Roll out the 2 sheets together to the diameter of the tray you're going to be baking in (mine was 11 3/4″ (30 cm)).
Place the double sheet in the tray that you've smeared with lard. Smear it with 2 tbsp sour cream (I used yoghurt) and sprinkle with crumbled feta cheese.
Do the same for the other balls of dough. You're going to get 5 sheets. Don't smear the last one.
Cut the sheets into squares, then cover the tray with a towel. Leave it in a warm area to rise for about 30 min. Then smear them with beaten egg yolk, oil and a little water.
Bake the Secenica at 356°F (180 °C) until golden.