Where hamburger should be successful? (2,1,4)
I believe the answer is:
on a roll
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" .)