Turkey election: Erdoğan faces his greatest challenge yet

There was a moment when Turkey’s election debate came down to an onion and a warship. 

It began when Kemal Kılıçdaroğlu, the man leading the charge to break President Recep Tayyip Erdoğan’s grip over Turkish politics, sat at his kitchen table last month, his shirt collar open, sleeves rolled up, and held up an onion.