Put outside nine mixes for a pignoli seed (4,3)
I believe the answer is:
pine nut
'seed' is the definition.
(seed of a pine tree)
'put outside nine mixes' is the wordplay.
'outside' is an insertion indicator.
'mixes' is an anagram indicator.
'nine' anagrammed gives 'inen'.
'put' placed around 'inen' is 'PINE NUT'.
'for a pignoli' acts as a link.
I am not very happy about this link. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Another definition for pine nut that I've seen is " Producer of evergreen".)