Dissolve the yeast in slightly warm water. Knead a soft dough. Divide it into balls the size of a large egg, cover with a towel to rest. Take a ball, grease it well and stretch it with your hands on top of the counter, crumble a little feta cheese on.
Take a second ball of dough and do the same thing, then put it on top of the first. Take the whole thing, put the ends together and form them into a ball. Place with the folded side down. Do this for all the balls.
Cover them with cloth, leave for 30-40 minutes to rise. Heat up a flat non-stick pan, smear it well with lard or butter. Take each ball, put it in and press with the tips of your fingers, to shape the pitas.
Ensure the cheese does not spill out, so it doesn't burn on the pan. Bake on one side, then turn over, smear the cooked side and then turn over once more to finish cooking.
Each time you turn it over, coat it lightly with lard or butter. Serve warm with cold ayran.