A slice of decent avocado in a little bread (7)
I believe the answer is:
centavo
'a little bread' is the definition.
(monetary unit in some countries)
'a slice of decent avocado in' is the wordplay.
'a slice of' says the answer is hidden in the clue.
'CENTAVO' is hidden in the letters of 'decent avocado in'.
(Other definitions for centavo that I've seen before include "money abroad" , "Foreign money" , "bit of money" , "money overseas" , "South American money" .)