Food not finished by setter dismissing starter as unappetising fare (5)
I believe the answer is:
gruel
'fare' is the definition.
(I have seen 'cheap fare' mean 'gruel' so perhaps 'fare' could also mean 'gruel')
'food not finished by setter' is the wordplay.
'food' becomes 'grub' (grub is a kind of food).
'not finished' means to remove the last letter.
'by' is a charade indicator (letters next to each other).
'setter' becomes 'el' (I can't justify this - if you can you should give a lot more credence to this answer).
'grub' with its last letter taken away is 'gru'.
'gru'+'el'='GRUEL'
'dismissing starter as unappetising' is the link.
This may not be correct. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for gruel that I've seen before include "sloppy fare" , "Thin liquid food" , "disappointing fare" , "Thin porridge" , "cheap fare" .)