Complicated problem puzzling cows on farm (3,2,5)
I believe the answer is:
can of worms
'complicated problem' is the definition.
'can of worms' can be an answer for 'problem' (I've seen this before). I am not certain of the 'complicated' bit.
'puzzling cows on farm' is the wordplay.
'puzzling' is an anagram indicator.
'cows'+'on'+'farm'='cowsonfarm'
'cowsonfarm' with letters rearranged gives 'CAN OF WORMS'.
Can you help me to learn more?
(Other definitions for can of worms that I've seen before include "which shouldn't be opened" , "amateur angler's bait?" , "this may turn out awkward" , "Something likely to prove awkward" , "Potential trouble" .)