In another bowl, beat the egg. Set aside a little of it for smearing the pita. To the rest of the egg add 4 tbsp oil and stir slightly until homogeneous. To them pour in the yoghurt and baking soda.
After the baking soda is extinguished, stir all of the liquid ingredients to a homogeneous, smooth mixture. Add 1/2 the floury mixture and stir energetically until it's absorbed. Then gradually add flour until it becomes thick to the point where stirring with the spoon becomes impossible.
Pour it onto the counter and knead with your hands until all of the listed amount of flour is absorbed. If the dough becomes too sticky, don't worry - all flours are different, just add a little more flour.
Cover the kneaded dough in a bowl and leave it for 20 min. to relax. Smear an 11″ (28 cm) diameter form with 2 tbsp oil.
Place the dough in the tray, shape it into a pita by pressing on it evenly, smear with the set aside egg and bake at 338°F (170 °C) until ready - about 30 min.
Smear the hot pita with butter, cover with a towel and leave to cool for about 30 min.