Sift the flour, salt and baking soda into a large bowl; beat the egg and add it to the flour with the sugar, yogurt and water.
Mix to a fairly soft dough, adding more water if necessary.
Add the ghee and knead the dough until it is smooth and pliable; put it back in the bowl, cover with a damp cloth and put in a warm place for about 4 hours to rise.
Knead the dough again and divide into ten balls; roll out each one on a greased board to a circle about 4 inches in diameter.
Heat the oil in a deep frying pan or wok and fry the bhaturas, one at a time turning them so that they tur that they turn pale golden on both sides; drain on paper towels and keep warm while you fry the remainder.
Note: This cookbook has a picture included of the bhaturas frying in a large deep frying pan that seems to contradict the instruction to fry one at a time.
In the picture all ten are frying at once.
My guess is that the instruction is meerly to make sure you have enough room to be able to turn them over and brown the other side.
The 5 hours prep time includes the 4 hours rising, and the 30 minutes cooking time is an approximation that will depend on how many you try frying at a time and how quickly they brown.