Take dimensions and cut the mustard (7,2)
I believe the answer is:
measure up
This clue is a double definition.
'take dimensions' is the first definition.
(I've seen this before)
'cut the mustard' is the second definition.
(I've seen this before)
'and' is the link.
(Other definitions for measure up that I've seen before include "Reach required standard" , "Reach the expected standard" , "adequate for the job?" , "take dimensions" , "Pass" .)