Look after work containing tangle of Mexican fruit (9)
I believe the answer is:
tomatillo
'mexican fruit' is the definition.
(fruit grown in Mexico)
'look after work containing tangle' is the wordplay.
'look' becomes 'lo' ('lo' is an archaic exclamation meaning 'look!').
'after' means one lot of letters go next to another.
'work' becomes 'toil' (toiling is a kind of working).
'containing' is an insertion indicator.
'tangle' becomes 'mat' (synonyms).
'toil' going around 'mat' is 'tomatil'.
'lo' put after 'tomatil' is 'TOMATILLO'.
'of' acts as a link.
(Other definitions for tomatillo that I've seen before include "Mexican food" , "plant" , "Green fruit" , "fruit in Mexico" .)