How to make
Dissolve the baking soda in the yoghurt. Once effervescent, add it to the flour, mixed with the salt. Stir with a wooden spoon. Add the crumbled feta cheese and stir again.
Gradually add the hot water, so as to make a soft dough. If necessary, add a little flour or water. With greased hands, make balls and arrange them in a tray with spaces in between, because they swell during baking.
Stick a piece of butter in each, sprinkle them with cheese and bake at 390°F (200 °C) until browned.