Posh student splits poor pasta utensil (7)
I believe the answer is:
spatula
'utensil' is the definition.
(I know that spatula is a type of food turner)
'posh student splits poor pasta' is the wordplay.
'posh' becomes 'u' (abbreviation for upper-class - opposite to non-U).
'student' becomes 'l' (as in L-plates for learner drivers).
'splits' indicates putting letters inside (inserted letters split open the word).
'poor' indicates anagramming the letters.
'u'+'l'='ul'
'pasta' is an anagram of 'spata'.
'ul' inserted within 'spata' is 'SPATULA'.
(Other definitions for spatula that I've seen before include "Implement with a broad, flat blade" , "Broad implement for mixing or spreading" , "flat mixer" , "Implement for mixing/spreading" , "Broad spoon" .)