What's provided in lunch and tea (3)
I believe the answer is:
cha
'tea' is the definition.
(cha is a type of tea)
'what's provided in lunch and' is the wordplay.
'what's provided in' indicates the answer is hidden within the clue.
'CHA' can be found hidden inside 'lunch and'.
(Other definitions for cha that I've seen before include "Tea (colloquial)" , "Tea (informal)" , "not allowed in ski lodge" , "Indian tea" , "Rosie Lee (slang)" .)