Best to drink with the engineers (7)
I believe the answer is:
supreme
'best' is the definition.
(I've seen this before)
'drink with the engineers' is the wordplay.
'drink' becomes 'sup' (I've seen this before).
'with' is a charade indicator (letters next to each other).
'the engineers' becomes 'reme' (I've seen this in other clues).
'sup'+'reme'='SUPREME'
'to' is the link.
(Other definitions for supreme that I've seen before include "Crowning" , "Creamy sauce" , "Highest in rank - incomparable" , "Chief" , "Ranked highest" .)