Sample portion of pasta's terrible (6)
I believe the answer is:
Here is my best explanation:
'sample' is the definition.
'portion of pasta's terrible' is the wordplay.
'portion of' says the answer is hidden in the clue.
'TASTER' is hidden in the letters of 'pastas terrible'.
(Other definitions for taster that I've seen before include "Food tester", "Quality assurance worker", "One trying", "Art set (anag.)", "She samples", "A professional savourer, of wine or tea", "person in charge of testing", "extract", "Sampler of food" and "Winery worker".)