Mash the feta cheese with a fork, grate the cheese on a fine grater. Put the yoghurt and baking soda in a bowl, stir until it bubbles. Add the oiled, mashed feta and cheese.
Begin stirring the mixture while adding the flour, stir until you get a sticky dough.
Form balls the size of an egg from the dough, arrange them some distance apart in a tray with baking paper (if you don't have baking paper, smear the tray lightly with oil and sprinkle with flour). The goal is to prevent them from sticking.
It's best to dip your hands in warm water before forming each ball, to prevent the dough from sticking to them.
Stick a cold butter cube piece in the middle of each lazy bun. Put the tray in a preheated 374°F (190 °C) oven and bake to a golden crust.
Leave the ready buns to cool for a few min., then they're ready to serve.