In entering the Foreign Office, one gets a sherry (4)
I believe the answer is:
fino
'a sherry' is the definition.
(I've seen this before)
'in entering the foreign office' is the wordplay.
'entering' indicates putting letters inside.
'the foreign office' becomes 'FO' (abbreviation).
'in' going into 'fo' is 'FINO'.
'one gets' acts as a link.
I am not very happy about this link. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for fino that I've seen before include "Light dry sherry" , "Dry Spanish sherry" , "Driest of the sherries" , "Type of sherry" , "Light-coloured sherry" .)