Complaint by volunteers once about English drink (4,3)
I believe the answer is:
beef tea
'drink' is the definition.
(I've seen this before)
'complaint by volunteers once about english' is the wordplay.
I cannot really understand how this works, but
'complaint' could be 'beef' (I've seen this in another clue) and 'beef' is located in the answer.
'about' could be 'a' (abbreviation in Chambers) and 'a' is found within the answer.
'english' could be 'e' (abbreviation) and 'e' is found within the answer.
A single letter 't' remains which might be clued in a way I don't see.
This may be the basis of clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for beef tea that I've seen before include "Savoury drink" , "Hot drink made with meat" , "Bovril" , "Juice from stewed meat for invalids" , "Drink made from boiled meat" .)