Improvise a bit of food (6)
I believe the answer is:
noodle
I believe this clue is a triple definition!
'improvise' is the first definition.
(noodle can mean to musically improvise)
'a bit' is the second definition.
(I have seen 'bit of pasta' mean 'noodle' so perhaps 'bit' could also mean 'noodle')
'of' acts as a link.
'food' is the third definition.
(noodle is a kind of food)
(Other definitions for noodle that I've seen before include "Slangy head or pasta strip" , "Simple person - in the soup?" , "may end up in the soup" , "String of pasta" , "Narrow strip of pasta, or foolish person" .)