Why fry onions without oil and then add oil? In several recipes I have seen lately, the instructions are to sautee onions and garlic without oil for a few minutes, and then add oil and continue until golden. If it's of any help, these are Ethiopian traditional recipes.

I know that the two processes are different, due to heat transfer by the oil, and the Maillard reaction etc. 
What could be the reason to start without oil and then add it though?
According to Wikipedia,


  the preparation of a wat begins with chopped onions slow cooked, without any fat or oil, in a dry skillet or pot until much of their moisture has been driven away. Fat (usually niter kibbeh) is then added, often in quantities that might seem excessive by modern Western standards, and the onions and other aromatics are sautéed before the addition of other ingredients. This method causes the onions to break down and thicken the stew.