Strand of pasta, old one cooked (6)
I believe the answer is:
noodle
'strand of pasta' is the definition.
'noodle' can be an answer for 'pasta' (noodle is a kind of pasta). I am not sure about the 'strand of' bit.
'old one cooked' is the wordplay.
'cooked' indicates anagramming the letters (letters cooked into a new form).
'old'+'one'='oldone'
'oldone' anagrammed gives 'NOODLE'.
Can you help me to learn more?
(Other definitions for noodle that I've seen before include "Thin strand of pasta" , "Ribbon-like strip of pasta" , "Fool (in the soup?)" , "may end up in the soup" , "Staple of Chinese cuisine" .)