Vague problem producing Chinese food (3,3)
I believe the answer is:
dim sum
'chinese food' is the definition.
(I've seen this before)
'vague problem' is the wordplay.
'vague' becomes 'dim' (I've seen this before).
'problem' becomes 'sum' (arithmetic problem).
'dim'+'sum'='DIM SUM'
'producing' is the link.
(Other definitions for dim sum that I've seen before include "Chinese appetiser" , "Selection of Chinese appetizers" , "something to take away?" , "Chinese fare" , "starters?" .)