A slice of chorizo needed, as far as one can see (7)
I believe the answer is:
horizon
'as far as one can see' is the definition.
(most distant point)
'a slice of chorizo needed' is the wordplay.
'a slice of' indicates a hidden word.
'HORIZON' is hidden in the letters of 'chorizo needed'.
(Other definitions for horizon that I've seen before include "The line at which the sky and the earth appear to meet" , "Distant line" , "As far as one can see" , "As far as the eye can see" , "Oz rhino (anag)" .)