A calm air about this fish dish (8)
I believe the answer is:
calamari
'this fish dish' is the definition.
'calamari' can be an answer for 'dish' (I have seen 'Dish of squid' mean 'calamari' so perhaps 'dish' could also mean 'calamari'). I am not sure about the 'this fish' bit.
'a calm air about' is the wordplay.
'about' indicates an anagram.
'a'+'calm'+'air'='acalmair'
'acalmair' with letters rearranged gives 'CALAMARI'.
Can you help me to learn more?
(Other definitions for calamari that I've seen before include "Battered squid rings" , "seafood" , "Mollusc" , "Mediterranean cooked squid" , "Dish of squid" .)