They might be curly sides I’ve cut (7)
I believe the answer is:
endives
'they' is the definition.
Both the definition and answer are plural nouns.
Maybe there's a link between them I don't understand?
'curly sides i've cut' is the wordplay.
'curly sides' becomes 'ends' (I can't justify this - if you can you should give a lot more credence to this answer).
'cut' is an insertion indicator (some letters cut their way into a word).
'ends' placed around 'ive' is 'ENDIVES'.
'might be' acts as a link.
Can you help me to learn more?
(Other definitions for endives that I've seen before include "Plants related to chicory, used in salads" , "'I'd seven plants, in a salad say (7)'" , "Herbs" .)