Food alas rehashed a lot (5)
I believe the answer is:
salad
'food' is the definition.
(salad is a type of food)
'alas rehashed a lot' is the wordplay.
I cannot really see how this works, but
an anagram of 'alas' is 'sala' which is present in the answer.
'lot' could be 'd' and 'd' is found in the answer.
No letters remain.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for salad that I've seen before include "Cold dish of vegetables or fruits" , "Counter serving cold vegetable dishes" , "A cold meal with lots of lettuce" , "Lettuce, cucumber etc" , "One that may be dressed for dinner" .)