One dreams about tucking into fresh pasties (8)
I believe the answer is:
escapist
'one' is the definition.
Although both the answer and definition are singular nouns, I cannot see how one could define the other.
'dreams about tucking into fresh pasties' is the wordplay.
I cannot really see how this works, but
'about' could be 'ca' (abbreviation for 'circa') and 'ca' is located in the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for escapist that I've seen before include "My interest is not of this world" , "One indulging in fantasy" , "One who lives in dreamland, a fantasist" , "One who tries to avoid the harsh world" , "One fleeing reality" .)