Sift the flour, baking soda and salt in a bowl. Add the yoghurt, mixed with the water and oil. Stir very well with a spatula to a thick and sticky mixture.
Lay out a tray with baking paper, pour the mixture into it, smooth out and sprinkle generously with sesame seeds. Heat the oven to 356°F (180 °C), place the tray in it, bake about 20-35 min.
Take the pita out of the oven, sprinkle with a little cold water and cover with a clean towel to smother for 10 min.
Serve the soda pita with a lump of feta cheese or just sprinkled with mixed spices.