All in, try to get something to eat (7)
I believe the answer is:
shallot
'something to eat' is the definition.
(shallot is a kind of food)
'all in try' is the wordplay.
'in' means one lot of letters goes inside another.
'try' becomes 'shot' (shot is a kind of try**).
'all' placed into 'shot' is 'SHALLOT'.
'to get' acts as a link.
(Other definitions for shallot that I've seen before include "One may get into a stew" , "bit of salad" , "Type of 12" , "Host all with kind of onion" , "Species of onion" .)