Doctor - tea or coffee? (5)
I believe the answer is:
mocha
'coffee?' is the definition.
(type of coffee drink)
'doctor tea' is the wordplay.
'doctor' becomes 'mo' (medical officer).
'tea' becomes 'cha' (cha is a type of tea).
'mo'+'cha'='MOCHA'
'or' is the link.
(Other definitions for mocha that I've seen before include "Fine-quality coffee" , "Fine quality coffee" , "It may end up as grounds" , "Coffee drink" , "Kid" .)