Indigestible food, for example, sent back (6)
I believe the answer is:
stodge
'indigestible food' is the definition.
'stodge' can be an answer for 'food' (stodge is a kind of food). I am not certain of the 'indigestible' bit.
'example sent back' is the wordplay.
'example' becomes 'eg' (short for 'exempli gratia', 'for example' in Latin).
'sent' becomes 'dots' (I can't explain this - if you can you should believe this answer much more).
'back' says the letters should be written in reverse.
'eg'+'dots'='egdots'
'egdots' back-to-front is 'STODGE'.
'for' acts as a link.
Can you help me to learn more?
(Other definitions for stodge that I've seen before include "Heavy and indigestible food" , "Heavy, often starchy, food" , "Heavy filling food" , "Indigestible or dull food" , "heavy fare" .)