Crossword Genius

Where hamburger should be successful? (2,1,4)

Ross

I believe the answer is:

I believe this is a double definition.

'where hamburger should be' is the first definition.

'successful?' is the second definition.

(Other definitions for on a roll that I've seen before include "Having long spell of good luck", "Going through a good patch", "Enjoying good luck", "Piano music was once stored here", "enjoying lots of success".)

I've seen this clue in Sydney Morning Herald.