Stew a couple of toads -- that's a problem (3,6)
I believe the answer is:
hot potato
'that's a problem' is the definition.
(hot potato can mean a controversial issue)
'stew a couple of toads' is the wordplay.
'stew' becomes 'hotpot' (I've seen this before).
'couple of toads' becomes 'to' (I can't justify this - if you can you should give a lot more credence to this answer).
'hotpot'+'a'+'to'='HOT POTATO'
Can you help me to learn more?
(Other definitions for hot potato that I've seen before include "tricky issue?" , "troublesome affair" , "A difficult situation" , "Troublesome situation for spicy spud" , "An awkward subject" .)