As far as 'B for Bucatini' (5)
I believe the answer is:
pasta
'b for bucatini' is the definition.
I can't tell whether this defines the answer.
'as far' is the wordplay.
I cannot really see how this works, but
'as' is found in the answer.
The remaining letters 'pta' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...
'as' acts as a link.
Can you help me to learn more?
(Other definitions for pasta that I've seen before include "Italian foodstuff" , "shells, perhaps" , "Eg, spaghetti" , "Fusilli, penne etc" , "Fusilli, conchiglie and penne" .)