"Chief's Special" was Quark's name for the breakfast order his brother Rom asked for every morning after work. According to Rom, it was "Chief O'Brien's breakfast of choice." The Chief's Special consisted of two eggs, over easy with three strips of bacon and a side of corned beef hash. Quark considered the choice to be a disgusting habit which Rom had acquired from his Human co-workers, in comparison to his brother's usual meal of puree of beetle.
After Rom was promoted to the day shift in 2373, he changed his breakfast order, partly because he found bacon didn't agree with his stomach, from the "Chief's Special" to the day shift's breakfast of choice: a short stack of pancakes, dripping with butter, a side of sausage and pineapple. (DS9: "The Assignment")