Pour the kefir into a bowl, add the sugar, salt and baking soda.
Stir with a whisk, add the egg and oil. Sift the flour, mix it with the other ingredients and work into a smooth dough.
Cut the dough into smaller, approximately equal pieces, shape into balls and then roll them out into discs about 5 - 6 mm thick. Make a short incision in the middle with a sharp knife.
Place the discs into hot oil, where they will puff up beautifully within a few seconds. Fry until golden, then place on paper towels to absorb the excess oil.