Pancake containing a lot of fish sauce (7)
I believe the answer is:
tabasco
'sauce' is the definition.
(Tabasco is an example)
'pancake containing a lot of fish' is the wordplay.
'pancake' becomes 'taco' (I've seen this before).
'containing' is an insertion indicator.
'a lot of fish' becomes 'bas' (I can't justify this - if you can you should give a lot more credence to this answer).
'taco' going around 'bas' is 'TABASCO'.
Can you help me to learn more?
(Other definitions for tabasco that I've seen before include "Mexican state; pungent sauce" , "condiment?" , "ASBO Act (anag) - hot stuff!" , "A hot spicy sauce" , "Chilli sauce" .)